Imam Sadiq (peace be upon him)- Yunus ibn Ya'qub said: A group of the companions of Imam Sadiq (peace be upon him), among whom were Humran ibn A'yan, Mu'min al-Taq, Hisham ibn Salim and al-Tayyar, and with them Hisham ibn al-Hakam, who was a young man, were in his presence. The Imam (peace be upon him) said: "O Hisham." He said: "At your service, O son of the Messenger of Allah (peace be upon him and his family)!" He said: "Will you not tell me what you did with Amr ibn Ubayd?" He said: "May I be your ransom! I hold you in awe and feel shy before you, and my tongue does not move in your presence." Imam Sadiq (peace be upon him) said: "When I command you to do something, do it." Hisham said: "News reached me of the position Amr ibn Ubayd held and of his sitting in the mosque of Basra, and this weighed heavily on me. So I set out for him and entered Basra on a Friday, and I came to the mosque of Basra. I saw a large gathering, and there was Amr ibn Ubayd wearing a black woollen wrap and another wrap thrown over his shoulder, and the people were questioning him. I made a way through the people and went and knelt before him, and I said: 'O scholar, I am a stranger; do you allow me to ask you a question?' He said: 'Yes.' I said: 'Do you have eyes?' He said: 'My son, what kind of question is this?' I said: 'This is my question.' He said: 'My son, ask, even if your question is foolish.' I said: 'Answer me.' He said: 'Ask.' I said: 'Do you have eyes?' He said: 'Yes.' I said: 'What do you see with them?' He said: 'Colours and persons.' I said: 'Do you have a nose?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'With it I smell scents.' I said: 'Do you have a mouth?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'I perceive the taste of things.' I said: 'Do you have a tongue?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'I speak.' I said: 'Do you have an ear?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'I hear sounds.' I said: 'Do you have a hand?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'I strike.' I said: 'Do you have a heart?' He said: 'Yes.' I said: 'What do you do with it?' He said: 'With it I distinguish everything that comes upon these organs.' I said: 'Do not these organs themselves make you independent of the heart?' He said: 'No.' I said: 'How is that, when they are all sound and healthy?' He said: 'My son, when the organs are in doubt about something they have smelled, seen, tasted, heard or touched, they refer it back to the heart, and doubt is dispelled and certainty is attained.' I said: 'So Allah has established the heart to remove the doubt of the organs?' He said: 'Yes.' I said: 'Then the heart is necessary, otherwise the organs cannot function properly.' He said: 'Yes.' I said: 'O Abu Marwan, Allah the Exalted in mention has not left the organs of your body without appointing for them an imam who confirms for them what is correct and gives certainty in what they doubt; and yet He has left all these creatures in their bewilderment, doubt and disagreement and not appointed an imam for them to whom they may refer their doubt and bewilderment, while He has appointed for you an imam for your organs to whom you refer your bewilderment and doubt?' He fell silent and said nothing, then turned to me and said: 'Are you Hisham?' I said: 'No.' He said: 'Are you a companion of his?' I said: 'No.' He said: 'Where are you from?' I said: 'From the people of Kufa.' He said: 'Then you are he.' And he embraced me and seated me in his place, and did not speak until I got up." Imam Sadiq (peace be upon him) laughed and said: "O Hisham, who taught you this?" I said: "O son of the Messenger of Allah (peace be upon him and his family), it flowed upon my tongue." He said: "O Hisham, by Allah, this is written in صُحُفِ إِبْراهِیمَ وَ مُوسی [the scriptures of Ibrahim and Musa]."