Praise be to Allah, the One and only God:
The eternal refuge, who did not beget, nor was He begotten. Nor is there anyone equal to Him (Qur.112) .
Far exalted is He over having mate or offspring, or being subject to number and effort. Sanctified over resemblances is His essence. His greatness transcends the minds of men, and His majesty has baffled the subtleties of human reason. Through clear testimony does His proof shine forth, and His wisdom is manifest in all things. He established truth, and made clear His proofs and elucidations through the beacons (that is, the Imams) and the clear evidences which He raised up. He destroyed falsehood, as He utterly refuted its errors.
Allah's blessings be upon His chosen servant and Prophet, the most excellent of prophets and messengers, and of people who have come and those who are yet to be ‑ the bearer of glad tidings who invited men to Allah by His leave, the luminous lamp (see Qur'an. 33:45‑6) and master of the masters of the Arabs and non‑Arabs ‑ Muhammad ibn `Abdillah ibn `Abdi 'l‑Muttalib.
Peace be upon his vicegerents, the rightly guided Imams, who are satisfied with Allah's pleasure: they who are the chosen of Muhammad's fragrant shoot; who are the guardians of his sacred law; they who are protected (by Allah) from all impurity and abomination; they who are chosen over all humankind and the jinn. Through them anyone promised good by Allah shall receive His promise; nor will anyone be able to traverse the sirat 1, except by their permission. They are the cushion of the middle course (upon which all must lean).2
Anyone who seeks to precede them shall go astray, and he who turns away from them shall perish. Yet he who abides with them shall achieve his goal. They are like the gate of forgiveness (bab hittah),3 and like the Ark of Noah ‑ he who enters it shall be saved, arid he who abandons it shall drown and perish. They are the elect of the Apostle and the chosen of his descendants. Allah linked their knowledge to knowledge of the Prophet, and made love for them as binding as love for him. They are the foundations of Islam: the Imams of humankind and the proofs of the Guardian, the (Lord of ) Peace4.
They are lamps in the darkness and guides to every desire. The best of blessings and peace be upon them, so long as lightening flashes, clouds pour down their rain and gardens adorn themselves with fruits and herbage.
(The author) has thus determined to write a book containing the names of the guiding Imams: the masters of authority, the people of command, the people of remembrance (see Qur'an. 4:59 and 16:43 ) and the people of the household of revelation from whom Allah has removed all impurity, and purified with a great purification5 (. It shall contain their biographies: the times of birth, and the spans of their lives and reports of their private lives and righteous deeds. It shall present proof texts supporting the truth of their imamate, as well as the signs which Allah manifested concerning them and which testify to their exalted status over all others.
The author contemplated all this, pondering it well, then said to himself: “If indeed the Apostle of Allah is the tree of which the Imams are the branches, the garden of which they are the flowers, the wellspring of knowledge of which they are the repositories, the essence of wisdom of which they are the treasurers, the legislator of the religion of which they are the keepers, and the recipient of the Book of which they are the bearers; he would then be more worthy to be first mentioned. The miracles which bespeak his apostleship, the signs pointing to the truth of his Prophethood, his great miracles and incontrovertible proofs, must all be set forth.
He thus sought Allah's aid in beginning and completing such a work, and entitled it ” I`lamu 'l‑wara bi a A`lami 'l-huda ”. He divided it into four parts: the first deals with the Messenger of Allah; the second concerns itself with the Commander of the Faithful, 'Ali ibn Abi Talib; and the third deals with the Imams of his descendants, beginning with al‑Hasan ibn 'Ali and ending with al‑Hasan al‑`Askari (the eleventh Imam), peace be upon them. The fourth and final part discusses the imamate of the twelve Imams, as well as the twelfth Imam. Each part is in turn divided into different chapters and sections, rich with precious knowledge and wisdom, each separately and all together.
For in this book I have brought forth a brilliant pearl for the hearts of the faithful, and the noblest sounds to be poured upon the ears of the people of certainty. Allah the Exalted grants support; He guides to the right course and to wise counsel. In Him do I trust, and to Him do I turn.