Among the shaykhs of the followers of Abu Abd Allah, peace be on him, his special group (khassa), his inner circle and the trustworthy righteous legal scholars, may God have mercy on them, who report the clear designation of the Imamate by Abu Abd Allah Jafars peace be on him, for his son, Abu al- Hasan Musa, peace be on him, are: al-Mufaddal b. Umar al-Jufi, Mu'adh b. Kathir, Abd al-Rahman b. al-Hajjaj, al-Fayd b. al-Mukhtar, Yaqub al-Sarraj, Sulayman b. Khalid, Safwan al-Jammal, and others whom it would make the book too long to mention.
(That designation) is also reported by his two brothers, Ishaq and Ali, sons of Jafar, peace be on him. They were men of merit and piety and (therefore reliable witnesses) in so far as two such men did not differ on it.
Musa al-Sayqal reported on the authority of al-Mufaddal b. Umar al-Jufi, may God have mercy on him, who said:
I (i.e. al-Mufaddal b. Umar al-Jufi) was with Abu Abd Allah (Jafar), peace be on him. Abu Ibrahim Musa, peace be on him, came in. He was still a boy. Abu Abd Allah Jafar, peace be on him, said to him: "Indicate to those of your Companions whom you trust that the position of authority belongs to him Musa."
Thubayt reported on the authority of Muadh b. Kathir, on the authority of Abu Abd Allah Ja'far:
I (i.e. Muadh b. Kathir) said to (Jafar): "I ask God, Who provided your father with you for this position, to provide you with one of your offspring for the same position before your death."
"God has done that," he answered.
"May I be your ransom, who is it?" I asked.
He indicated al-Abd al-Sarh (the pious worshipper of God) (i.e. Musa) to me. He was asleep.
"This one who is sleeping," he said. He was at that time a boy.
Abu Ali al-Arrajani reported on the authority of Abd al Rahman b. al Hajjaj, who said:
I (i.e. Abd al-Rahman b. al-Hajjaj) visited Jafar b. Muhammad, peace be on them, in his house. He was in such-and-such a room in his house which he used as a prayer-room. He was praying there. On his right hand was Musa b. Jafar, peace be on them, following his prayer.
"May God make me your ransom," I said, "you know how I have dedicated my life to you and (you know of) my service to you. Who is the master of the affair (wali al-amr) after you?"
He said: "Abd al-Rahman, Musa has put on the armour and it fitted him."
"After that, I have no further need of anything," I replied.
Abd al-Ala reported on the authority of al-Fayd b. al-Mukhtar, who said:
I (i.e. al-Fayd b. al-Mukhtar) said to Abu 'Abd Allah Ja'far, peace be on him: "Take my hand away from the fire (of Hell). Who is (the Imam) for us after you?"
Abu Ibrahim (Musa) entered - at that time he was a boy. Then (Jafar) said: "This is your leader (sahib). Keep close to him."
Ibn Abi Najran reported on the authority of al-Mansur b. Hazim, who said:
I (i.e. al-Mansur b. Hazim) said to Abu 'Abd Allah, peace be on him: "(May I ransom you) with my father and mother. There is a great coming and going among men about (the succession). Since that is so, who is it?"
"Since that is so," replied Abu 'Abd Allah, peace be on him, "he is your leader."
He tapped the right shoulder of Abu al-Hasan (Musa). He was at that time, as far as I know, about five years old. 'Abd Allah b. Ja'far was sitting with us.
Ibn Abi Najran reported on the authority of Isa b. 'Abd Allah b. Muhammad b. Umar b. Ali b. Abi Talib, on the authority of Abu Abd Allah Ja'far, peace be on him:
I (i.e. 'Isa b. Muhammad) asked (Ja'far): "If something happened - may God not make me see such a thing - who should I follow?"
(Ja'far) pointed to his son, Musa.
"If anything happened to Musa, who should I follow?" I asked.
"His son," he replied.
"If anything happened to his son?"
"Then his son."
"If something happened to him," I went on, "and he left a big brother and a small son?"
"His son; it is always thus," he answered.
Al-Fadl reported on the authority of Tahir b. Muhammad on the authority of Abu 'Abd Allah Ja'far, peace be on him:
I (i.e. Tahir b. Muhammad) saw (Ja'far) blaming his son, 'Abd Allah, and warning him. He was saying: "What stops you from being like your brother? By God, I see the light in (Musa's) face."
"Why is that?" asked 'Abd Allah. "Is not my father and his father one and the same? Is not my origin and his origin one and the same?"
"He is from my soul and you are my son," replied Abu 'Abd Allah Ja'far, peace be on him.
Muhammad b. Sinan reported on the authority of Ya'qub al- Sarraj), who said:
I (i.e. Yaqub al-Sarraj) visited Abu 'Abd Allah Jafar, peace be on him. He was standing by the head of Abu al-Hasan, Musa, peace be on him, who was in the cradle. He began to play with him for a long time. I sat down until he had finished. Then I stood up before him. He told me: "Approach your master (mawla) and greet him."
I went near him and greeted him and he replied to me eloquently. Then he told me: "Go and change the name of your daughter which you gave her yesterday. For it is a name which God dislikes."
A daughter had been born to me and I had named her al-Humayra'.
"Pay attention to the command which he gave you," Abu Abd Allah Jafar, peace be on him, told me. So I changed her name.
Ibn Miskan reported on the authority of Sulayman b. Khalid, who said:
One day Abu Abd Allah Jafar, peace be on him, called for Abu al-Hasan Musa while we were with him. He told us: "It is your duty (to follow) this man after me. By God, he is your leader after me."
Al-Washsha' reported on the authority of Ali b. al-Husayn, on the authority of Safwan al-Jammal, who said:
I (i.e. Safwan; al-Jammal) asked Abu Abd Allah Jafar, peace be on him, about the leader of this affair (sahib al-amr) (after him). He said: "The leader of this affair is one who does not fool and play."
Abu al-Hasan Musa, peace be on him, approached. He was still small. He had a calf (destined) for Mecca and was saying to it:
"Prostrate yourself to your Lord."
Abu Abd Allah Jafar, peace be on him, took him by the hand and embraced him saying: "May I ransom with my father and mother (you) who do not fool and play."
Yaqub b. Jafar al-Jufi reported: Ishaq b. Jafar al-Sadiq, peace be on him, told us:
One day I (i.e. Ishaq) was with my father (Jafar) when Ali b. Umar b. 'Ali asked him: May I be your ransom, to whom shall we and the people turn after you?"
He answered: "To the owner of two yellow clothes and two locks of hair. He who is coming out of the door to you."
We did not wait long before two (little) hands appeared pulling the two doors so that they opened. In before us came Abu Ibrahim Musa, peace be on him. He was still a boy and was wearing two yellow garments.
Muhammad b. al-Walid reported: I heard Ali b. Jafar b. Muhammad al-Sadiq, peace be on them, say:
I (i.e. 'Ali b. Jafar) heard my father, Jafar b. Muhammad, peace be on them, say to a group of his close associates and followers:
"Treat my son, Musa, peace be on him, with kindness. He is the most meritorious (afdal) of my children and the one who will succeed after me. He is the one who will undertake (qa'im) my position. He is God's proof (hujja) to all His creatures after me."
Ali b. Jafar remained firmly loyal to his brother Musa, peace be on him, devoted to him, and enthusiastic in taking the outlines of religion from him. He has a famous (book) Masa'il (questions) in which he relates the answers he heard from (Musa), peace be on him.
The reports of what we have mentioned are too numerous to be explained and described fully.