'Abdul 'Ala, the son of 'Ayun, set out from Kufah for Madinah. Friends and followers of Imam al-Sadiq ('a) in Kufah took this opportunity to write many imperative questions and handed them over to Abdul 'Ala so that he would bring them back the answers given by the Imam ('a ).
They also asked him to inquire orally about a particular question relative to the rights which a Muslim had upon another Muslim from the legal point of view and bring his reply too.
Abdul 'Ala arrived in Madinah and went to the presence of the Imam ('a). He handed the written questions to the Imam ('a) and brought up the oral problem. But contrary to his expectation, the Imam ('a) replied to all of the questions with exception of the latter. 'Abd ul 'Ala did not say anything that day and went off.
The next day, the Imam ('a) did not say anything about the question. When Abdul 'Ala was about to leave Madinah, he went to the Imam ('a) to bid farewell. He thought to expose again his question; thus he said: "O descendant of the Messenger of Allah! You have not replied to my question yet."
The Imam al-Sadiq ('a) said: "I did not answer to it intentionally."
"Because I fear to tell the truth and you do not carry it out and then leave the religion of Allah!"
The Imam ('a) continued his words and said: "In fact, among the most difficult duties facing the creatures of Allah, there are three of them:
Firstly, respecting the justice and equity between himself and the others to such an extent that he behaves towards his Muslim brother just as he likes to see the others behave towards him.
Secondly, not refusing his property with the Muslim brothers in giving them a hand.
Thirdly, remembering Allah in all circumstances. I do not mean by that to go on repeating “Subhana Allah”1 or "Al-hamdu lil-Lah"2 unceasingly, but I would like to say that one should be in such an attitude that if he faces an illegal action (Haram), while the remembrance of Allah always being in his heart, will prevent him from committing it.3