You should know that waswasah (or waswas, pl. wasawis; means satanic insinuations, obsessions and suggestions), doubt, lapse of faith, shirk and the like pertain to satanic insinuation and devilish promptings, which Satan puts into the hearts of people. So also, certainty, conviction, tranquillity, steadiness and sincerity of the heart and the like are caused by divine inspiration (ifadat-e rahmaniyyah) and angelic suggestions (ilqa'at-e malakiyyah). To explain this with brevity, the human heart is a subtle reality that is interjacent to the realms of mulk and malakut, the realms of the world (dunya) and the Hereafter. One of its aspects faces the realm of mulk and the (mundane) world, and it is with this aspect that it pursues the corporeal aspect of life. The other aspect faces the realm of Hereafter, malakut and ghayb, and with that it pursues its spiritual (malakuti) life.
Hence the heart is like a two-faced mirror. One of its sides is turned toward the world of ghayb, and in it the ghaybi forms are reflected. The other side faces the world of shahadah, and in it the mulki and worldly (mundane) forms are reflected. The mundane forms find their reflection in the outward senses and some of the inner cognitive faculties such as khayal and wahm (imagination). The hereafterly forms find their reflection in the inward intellect and the inner core (sirr) of the heart. Should the worldly aspect of the heart preponderate and its attention be wholly absorbed by the pursuit of the mundane, becoming its sole concern, the hidden side of khayal becomes attuned to the realm of lower malakut (malakut-e sufla) which is the dark reflected image of the world of mulk and corporeal nature (in the realm of malakut)-the realm of the jinn, devils and evil spirits. The suggestions induced in it due to this attunement (with the realm of lower malakut) are satanic insinuations, which are the source of baseless thoughts and unwholesome imaginings. The soul develops an eagerness for these unfounded fancies due to its absorption with the mundane, and its will and faculty of decision-making also become subject to them. As a result, all one's spiritual and bodily conduct becomes satanic in character, as is the case with waswas, doubt, uncertainty, unfounded thoughts and hallucinations. As the will in its bodily activity becomes attuned to them, bodily actions too assume the character of the inward forms; for one's acts are the image of one's will, which in turn is the image of one's thoughts. which are a reflection of the heart's orientation. Hence, when the heart be oriented toward the satanic realm, the suggestions it receives are of a satanic character, involving compound ignorance. As a result, waswas, doubt, .irk and ambiguities emerge from the inner core of one's being and pervade to the domain of the body.
In accordance with the same analogy, if the heart be oriented toward the pursuit of the Hereafter and the higher truths, its attention is directed towards the world of ghayb and it acquires an attunement with the higher malakut, the realm of the angels and blessed and pure spirits, which is a luminous image of the world of nature. The knowledge imparted to it, then, is of a divine and angelic character, as constituted by true doctrine, and its thoughts are induced by divine inspiration, being free from the contamination of doubt and shirk. As a result, a state of stability and bliss is created within the soul. Its desires and inclinations fall into conformity with that knowledge, and its will into conformity with those inclinations, and, as a result, its inward and outward, spiritual and bodily conduct takes shape in accordance with the criteria of reason and wisdom. There are certain stages and stations associated with these satanic, angelic and divine suggestions whose description is not suitable here. Some of the noble traditions, like the following one reported in Majma` al-bayan from al-`Ayyashi, bear out the validity of what has been said:
Al-Ayyashi reports with his chain of transmission from Aban ibn Taghlib from Ja'far ibn Muhammad-may peace be upon the two of them-that he said: `The Messenger of Allah-may Allah's benedictions be upon him and his family-said: "There is no believer whose heart does not have two ears: an angel whispers into one of them and into the other the Slinking Whisperer (al-waswas al-khannas). God confirms the believer with the means of the angel and that is what is meant by this statement of His, subhanahu: "And He confirms them with a spirit from Him" ' "(58:22). 
This is another tradition from Majma' al-bahrayn:
He (i.e. the Prophet) said: "Satan lays his snout, which is like the snout of a pig, on the heart of the son of Adam, and instigates him to turn towards the world (dunya) and that which God has not made lawful. But when he remembers God, Satan slinks away." 
There are other traditions of this kind.
2. A Simpler Explanation of the Character of Waswas:
Having known through the teachings of the urafa' that waswas is the work of Satan, as mentioned in the noble tradition being expounded here and other traditions of the kind, we are compelled to explain this matter in a way that is closer to the minds of ordinary people and more appropriate for them. Although the above description is in accordance with the rational and philosophical criteria as well as in conformity with the mystical experience of the `urafa', `the people of the heart', as it is based on certain principles whose discussion lies outside the scope of these pages, we shall abstain from pursuing it any further. That wasawis and acts resulting from them are a handiwork of Satan, insinuated by that accursed creature, and that there is therein no religious or pious motive involved-although the person afflicted may mistakenly believe that he possesses it-is borne out by their being contrary to the laws of the Shari'ah and the traditions of the pure and infallible Imams of the Ahl al-Bayt.
For instance, it has been mentioned in mutawatir traditions of the Ahl al-Bayt-may peace be upon them-that the wudu' of the Messenger of God-may God's benedictions be upon him and his Household-consisted of single washings (of the face and the forearms). It is an established fact in fiqh that it is sufficient to wash the face, the right and the left hand each with-a single ghurfah (handful) of water. There is however disagreement among the legists concerning the permissibility of using a second ghurfah. It may even be inferred from the statements of the author of al-Wasa'il that he believed in its impermissibility or at least doubted its permissibility. Although some have held a contrary opinion, the permissibility of two washings is not open to doubt. There is a heavy preponderance of legal opinion in its favour and many traditions indicate its istihbab. However, it is not improbable that a single washing that thoroughly wets the parts washed is preferable. But there is no doubt that three washings-that is, washing the parts each time in such a way that the parts are thoroughly moistened with water-is haram and a bid'ah that invalidates the wudu' when the moisture remaining from it is used for mash. It is mentioned in the traditions of the Ahl al-Bayt-may peace be upon them-that a third washing in wudu` is bid'ah and that every bid'ah is in Fire.
In this case, the ignorant man afflicted with waswas washes the parts ten times during wudu', every time drawing water over the whole part washed most meticulously, or rather he first wets the whole part so well that water spreads thoroughly and a valid washing is achieved, and then repeats this action again and again. On what criterion is his action based? To which tradition and to what fatwa of a jurist does it conform? Such a wretch may offer invalid salat with such a wudu' for twenty years and consider himself to have appeared to be most pious and pure in the eyes of the people. While Satan goes on playing with him and his carnal self goes on deceiving him, he finds fault with others and considers himself to be in the right.
Should something that is opposed to mutawatir explicit dicta (nass) and consensus of the `ulama' be considered as perfect personal purity and piety or a work of Satan? If it is something that is inspired by utmost God-fearing and caution in religion, why is it that most of those obsessed by waswas and given to ignorant sanctimony do not exercise caution in matters where caution is necessary or preferable? Have you seen any waswasi who has waswas in dubious matters of a financial character? Has anyone ever come across someone affected with waswas who pays khums five times instead of once, or goes to Hajj several times instead of once? Or one who refrains from food of a doubtful character? Why is it that the rule of asalat al-hilliyyah  applies in such cases whereas the rule of asalat al-taharah  does not hold good even in a matter related to taharah itself? That, although in regard to things that are lawful there is greater reason to exercise abstinence in a doubtful matter as indicated by some noble traditions, like the hadith al- tathlih  whereas the case is quite the opposite in matters of taharah.
One of the Infallible Imams (A) used to sprinkle water with his blessed hand on his blessed thighs at the time of answering the call of nature so that any trace of splashing that might occur would not be visible. Yet this poor fellow, who considers himself a follower of this Infallible Imam and follows him in the precepts of his religion, does not abstain from anything in matters involving wealth and its consumption. He eats his food (without any qualms about its lawfulness) by relying on the principle of asalat al-taharah and having eaten cleanses his mouth and hands. While eating, his justification is asalat al-taharah, but after eating he declares that everything is ritually unclean (najis). Should he, in his fancy; count himself among the learned, he would say that I want to offer salat with real taharah , whereas the advantage of salat with real taharah is something that remains unknown and the fuqaha'-may God be pleased with them-do not know of it. Such a person should be asked, if you are so keen about real taharah, then why aren't you as keen about real hilliyyah (lawfulness)? Even if, supposedly, he were keen to achieve real taharah, what purpose is served by his washing ten times with kurr or jari water? (Although to obtain taharah it is sufficient to wash once with jari water and once with kurr water when the contamination is due to urine and certain other impurities. Even when it is due to urine, it is sufficient, in accordance with the mashhur opinion, to wash once with kurr water, and washing twice is considered sufficient by consensus.) These several washings are inspired by none other than the deceptive Satan and the tricky self which make an inconsequential matter appear as an asset to the sanctimonious.
Worse and more shameful than this is the waswasah of some in regard to niyyah and takbirat al-'ihram, for therein they commit several muharramat while they consider themselves to be among the pious and this act as bringing them some kind of merit. Niyyah (intention) in something without which man cannot perform any of his voluntary acts and it is something which necessarily accompanies all volt vary actions. Man cannot carry out any of his ritual or non-ritual acts without it. Notwithstanding it, in proportion to their devilishness and the degree of Satan's domination over them, they waste an entire hour and sometimes several hours in order to obtain what is an inescapable necessity, which in the end remains unachieved! Should this matter be regarded as a result of Satanic insinuation and the work of the accursed Iblis who has put his reins on this wretch and concealed an obvious necessity from him, involving him in many muharramat such as breaking the salat, neglecting it, and allowing its time to elapse, or as something that is inspired by inner purity, sanctity and God-fearing?
Another kind of waswas has to do with the refusal to join the congregation prayer led by someone who is 'adil in accordance with nass and fatwa due to the righteousness of his outward conduct and his dutifulness in regard to the Shari`ah, whereas only God knows his inner character, regarding which it is neither necessary nor permissible to investigate. Notwithstanding it, since the person afflicted with waswas has his reins controlled by Satan, he draws himself away from the jama'at of Muslims and prays individually in a corner of the mosque. He offers such justifications as, `I have qualms' and `It does not satisfy me' and so on, while he himself has no qualms about leading others in prayer, despite the fact that the job of imamate is more difficult and is more open to qualms. However, he does not have any doubts or qualms here because that is in agreement with his self-seeking motives.
Of the forms of waswas that is more prevalent is the one that relates to qira'ah in prayer, wherein due to repetitive and excessive effort in gutturalization the sounds of letters often violates the rules of correct recitation or the shape of the word is totally changed. For instance, the word, dallin is pronounced by some in such a way that the dad sounds like qaf. The guttural ha' of rahman, rahim and other words is turned around in the throat in such a manner that a strange sound is produced and the letters of a word are so separated from one another that the very form, and root of the word is totally altered and distorted out of its original shape. Ultimately, all the spiritual aspects and divine secrets of salat, which is the spiritual ascension (mi'raj) of the faithful, the agent of nearness (to God) for the pious, and the pillar of the faith, are neglected, with all attention given to the `niceties' of recitation. And yet despite it all, the pronunciation of words is so corrupted that the recitation fails to meet the literal dicta of the Shari'ah. In view of this, should this (perverse obsession with qira'ah) be considered as satanic waswas or as a divine inspiration on the part of the sanctimonious person afflicted with waswas? Despite all these traditions relating to the presence of attention and attentiveness of the heart during worship, all that this poor fellow has understood concerning the theory and practice of the presence of heart is either to be obsessed with waswas concerning niyyah or and to twist to extend inordinately the long vowel (madd) of his mouth, eyes and other facial features while vocalizing words.
Is it not a misfortune that one should remain for years negligent concerning the presence of heart and the remedy of his disturbed mind, without ever thinking of taking a step in this regard, without regarding it as one of the significant aspects of worship and without learning the way of acquiring it from those learned in the matters of the heart? Is it not a calamity that by the side of this neglect he should be obsessed with this kind of absurdities, and consider as being essential to piety and inner purity what are a `work of the accursed Slinker' according to the express texts of the Noble Scripture and a `handiwork of Satan' according to the express traditions of the Truthful Ones-may peace be upon them-and acting upon which makes one's works invalid according to the verdicts of the fuqaha'?
At times waswasah is originated or heightened in one because other ignorant persons like himself consider it as one of his virtues. For instance, they extol his piety, religiosity and sacred character by remarking that `This person is so religious and pious that he is given to waswas', although waswas has not only no relation to religiosity but is contrary to it and is due to ignorance and absence of understanding. But since they do not tell him the truth and do not regard him with repulsion and disapprobation, but on the contrary praise and extol him, he pursues this vicious conduct to its extreme, making himself a plaything in the hands of Satan and his task force and banishing himself from the sacred company of those near to God.
And therefore, my dear, now that it is known through reason and tradition that these are satanic wasawis and that these obsessions are a handiwork of Iblis that invalidate our works and turn our hearts away from God, the Exalted, beware of them, for this waswas may not remain confined to your acts and may affect your belief and creed and thus expel you from the religion of God. By making you uncertain in your faith in God and Resurrection it may lead you into everlasting wretchedness. Since Satan cannot mislead the like of you into immoral and profane conduct, he approaches you by the way of worship and rites. First he makes your works and deeds, which should be a means of attaining divine nearness and of ascending into the proximity of God, the Exalted, to go waste and become invalid, and turns them into a means of remoteness from the proximity of the Sacred Lord, the All-Glorious, and of nearness to Iblis and his troops. Ultimately, it is feared, he may make a plaything of your beliefs. Hence, take steps for its remedy by all means and through any kind of exercise that may be necessary.
3. The Remedy for Waswas:
You should know that this malady of the heart, which like other diseases of the heart can lead man to everlasting perdition and endless wretchedness, can be cured very easily and simply by the means of beneficial knowledge and action. But first one must know himself to be sick, for only then can he take a step to cure his illness. But the difficulty is that Satan has so driven home his arguments that he does not consider himself to be sick. Rather, he considers others to be wayward and negligent of their religion.
As to the theory of remedy, it lies in contemplating about these matters as mentioned. It is good for a human being that his acts and deeds be based on reflection and thought. He should think about an action that he wishes to perform for the pleasure of God, the Exalted, as to from where and from whom he has derived its details. It is known that the common people learn them from the fuqaha' and their maraji taqlid (authorities on Law), who derive the manner of performing an act from the Book and the Sunnah by the means of ijtihad. Now when we refer to the works of the fuqaha, we find that they repudiate the conduct of one obsessed with waswas and consider some of his acts as invalid. When we refer to the noble traditions and the Book of God, we see that his conduct is ascribed to Satan and the perpetrator is considered to be devoid of intelligence. Hence when the case is such, an intelligent person should reflect and think for a while if Satan has not taken control of his mind. Then he must commit himself to setting aside this kind of conduct and correct it, for therein lies God's good pleasure.
Whenever someone finds a trace of this obsession in himself, he should turn to other ordinary people or question the `ulama' and fuqaha' about his own conduct to see whether he is suffering from waswas or not. That is because most of the time the one suffering from waswas is unaware of his own condition and considers himself as quite balanced and others as negligent. But if he should do some reflection he would find that this belief too is a satanic suggestion, for when he sees that the practice of the ulama' and the great scholars in whose knowledge and practice he has faith, or rather that of the legal authorities (maraji' taqlid) from whom all Muslims derive the issues of halal and haram, is contrary to his own practice, he cannot say that the entire class of `ulama', the leaders of the faith and its adherents are not committed to the religion of God and it is only the waswasi person who is committed to piety.
After that he has come to know in theory that he is ill, it is necessary to take remedial action. The main point that relates to action is that he should not pay attention to the satanic waswasah and the whims that it insinuates. For instance, if he is suffering from waswas in the matter of wudu', he should make use of a single handful of water despite Satan's protestation. His Satan may say that this act is not valid. To this he should reply by saying that `If my act is not valid, then the practice of the Messenger of God (S) and the Pure Imams (A), as well as that of all the fuqaha' was invalid too. The Messenger of God (S) and the Imams (A) performed wudu' for nearly three hundred years and the manner in which they performed it was like this according to mutawatir traditions. So if their wudu' was invalid, let mine also be such." If you are muqallid of a mujtahid, you may tell Satan: "I am acting in accordance with the ruling of a mujtahid. If my wudu' is invalid, God shall not consider me responsible, and He has no incriminating grounds (hujjah) against me." Should the accursed one cast doubt concerning the ruling of the mujtahid, saying that he did not give such a ruling, fetch his book, which is accessible, open it and show it to him. If you ignore his insinuations several times and act contrary to his suggestions, he would take his hands off you in desperation, and it is hoped that you will obtain a definite cure of your illness, as mentioned in some noble traditions:
In al-Kafi (al-Kulayni reports) with his isnad from Zurarah and Abu Basir that they said: "We asked him (i.e. al-Imam al-Baqir or al-Imam al-Sadiq-may peace be upon them) about a man who had frequent doubts in his salat, to the extent that he wouldn't know how much he has offered and how much remain to be offered. He said, 'He shou!d repeat (the salat)'. We said to him, 'That happens to him a lot and wherever he repeats his doubt also recurs.' The Imam said, '(In that case) he should ignore his doubt: Then he added, 'Don't let the Evil One get accustomed to haunting you by tempting him by breaking the salat. For Satan is wicked and gets accustomed to that which he is allowed to get used to. So when one of you does not pay attention to his doubt and does not break his salat frequently, and this is done a number of times, the doubt will not recur to him'." Zurarah says: "Then the Imam added: 'The Evil One wants to be obeyed, and when he is disobeyed he will not return to any of you.' " 
(Al-Kulayni) reports with his isnad from Abu Ja'far-may peace be upon him-that he said: "When sahw (i.e. forgetfulness, absent-mindedness, lapse of attention) occurs often to you during salat, disregard it, for that will make Satan leave you. Indeed sahw is due to Satan." 
Certainly, when you oppose his insinuations and do not pay attention to them, Satan will give up his hopes and the state of steadiness and certitude will return to your soul. But while you oppose him you must tearfully beseech God, the Exalted, and seek the refuge of His Sacred Essence from the evil of the Accursed One and from the evil of the carnal self. Of course, He shall help you. In the following tradition of al-Kafi too, we have been commanded to seek God's help against the evil of Satan:
Al-'Imam al-Sadiq-may peace be upon him-said: "A man came to the Messenger of Allah (S) and said: 'O Messenger of Allah, I complain to you concerning the waswasah that so troubles me during salat that I don't know how much of my prayer I have offered.' The Prophet said to him, 'When you enter your salat, strike your left thigh with the forefinger of your right hand, then say: "In the Name of God and by God, I put my trust in God, I seek refuge in God, the All-hearing, the All-knowing from Satan, the Stoned One." You will exorcize him and drive him away'." 
And all praise is God's, firstly and lastly, outwardly and inwardly, and may benedictions and peace be upon Muhammad and the Pure Ones of his progeny.
. Al-Kulayni, Usul al-Kafi, i, "kitab al-'aql wa al-jahl," hadith no. 10.
. Al-Tabrisi, Majma' al-bayan, x, 571.
. Majma' al-bahrayn, under "kh.n.s.," p. 305.
 Asalat al-hilliyyah means the rule that every thing is permissible unless there is evidence of its being forbidden.
. Asalat al-taharah means the rule that when a doubt occurs concerning the ritual purity of something which was known for certain to be pure before the occurrence of the doubt, the doubt is of no consequence and is to be ignored.
. Hadith al-tathlith refers to the following hadith recorded in Wasa'il al Shi'ah, xviii, 114: Al-Kulayni (in al-Kafi, i, 67, hadith no. 10) narrates from Muhammad ibn Yahya, from Muhammad ibn al-Husayn, from Muhammad ibn 'Isa, from Safwan ibn Yahya, from Dawud ibn al-Husayn, from 'Umar ibn Hanzalah that al-'Imam al-Sadiq (A)said (in a long hadith): "Matters fall into three categories: those whose rightness (or lawfulness) is evident and hence they are followed; those whose wrongness (or unlawfulness) is evident and hence are to be avoided; and those which are doubtful, regarding whose knowledge reference should be made to God and His Messenger. The Messenger of Allah (S) said: There is that which is evidently lawful (halal bayyin) and that which is evidently unlawful (haram bayyin), and between these there are things which are doubtful and suspect (shubuhat). One who abstains from doubtful things is saved from falling into unlawful things, and one who takes recourse in doubtful things falls in unlawful things and perishes without knowing it." At the end of the hadith the Imam remarks: "Abstaining from doubtful things is better than plunging into that which ruinous." The same tradition has been narrated by al-Saduq in Man la yahduruh al-faqih iii, 5, hadith no. 2 with his isnad from Dawud ibn al-Husayn, and by al-Shaykh al-Tusi in al-Tohdhib, vi, 301, hadith no. 52. It is called "hadith al-tathlith" because of the mention therein of the "three matters" (umur thalathah).
. Al-Kulayni, Furu' al-Kafi, iii, 358.
. Ibid., iii, 359.
. Ibid., iii, 358.