Imam al-Sadiq, peace be on him, informed his followers of the Imamate of his son Musa, peace be on him, when the world shone with his birthday. On every occasion he told them of that and asked them to keep that a secret for fear for them and his son of the ruling authority. When the Imam, peace be on him, was seventy years old, a group of his followers hurried to him to ask him about the Imam after him to pledge allegiance to him and to resort to him in respect with the affairs of their religion. He answered them that the Imam after him would be his son Musa, peace be on him; the following is the presentation of these texts:
1. Al-Mufaddal Bin 'Umar
Al-Mufaddal Bin 'Umar al-Ju'fi was among the prominent Shi'ites and one of their famous, great figures. He asked Imam Ja'far b. Muhammed, peace be on him, about the Imam after him to follow him and to adopt his Imamate, and he, peace be on him, answered: "Mufaddal, the Imam after me is my son Musa, the hoped, awaited successor."
2. Yazid Bin Sulayt
Yazid Bin Sulayt was trustworthy and trusted. He was among the men of piety and knowledge. He and a group of his companions made the pilgrimage to the Sacred House of Allah (Mecca). On his way, he met Imam Abu 'Abd Allah (al-Sadiq), who was accompanied by his sons and retainers. He hurried to the Imam to ask him about the Imam after him, saying: "May my father and mother be your ransom; you are the purified Imams; none escapes from death; who is the Imam after you?" The Imam, peace be on him, indicated with his hand to his son Musa and explained his ideals with which he was endowed. He said: "He has the knowledge of wisdom, understanding, generosity, knowledge of that which men need and of the affairs of their religion over which they differ. He has good manners and good neighborhood; he is one of Allah's gates; he has another (quality) that is the best of all these (qualities)."
-May my father and mother be your ransom, what is it?
-Allah, the Most High, will bring forth from him the succor of this community, its relief, its knowledge, its light, its understanding, and its wise man, the best baby and youth. Through him Allah will prevent bloodshed, correct discords, bring together the people of separation, make peace among (them), clothe the naked, satisfy the hungry, make the fearful safe, and send rain down. Men obey him; the best middle-aged one and young man; his words are a decision; his silence is knowledge; he explained to men that over which they differ."
The Imam, peace be on him, told them about that with which Allah had gifted his son such as that He placed among his progeny the rightly-guided one (Mahdi) of the family of Muhammed, may Allah bless him and his family, of whom the Prophet and the Imams after him gave good news. He will set right crookedness, the regulations of the world and the religion. He will not come till corruption prevails, oppression becomes public, chaos spreads, deviation from the religion becomes famous, the earth is full of discords and disorders; may Allah bring about his early reappearance, place us among those who summon to him and support him.