الكافي 1/4/75/8

8. Muhammad ibn Yahya and others have narrated from Sa‘id ibn ‘Abdallah from a group of banu Hashim, among whom was al-Hassan ibn al-Hassan al-Aftas, the following. “They were present on the day Muhammad ibn Ali ibn Muhammad, at the door of abu al-Hassan to offer condolences. A place in the compound of his house was prepared for him and people were sitting around him. They said, “We estimated that at that time from the descendents of abu Talib, Hashim and Quraysh there were about fifty men besides his slaves and other people. At such time he look at al-Hassan ibn Ali coming and the front of his shirt was torn. He stood at the right of his father and we did not know him. Abu al-Hassan عليه السلام looked at him after a while and said, “My son, renew your thanks to Allah, the Most Majestic, the Most gracious, because He has granted you a new task (Leadership with Divine Authority).” The young man wept, praised Allah, and said, “We are for Allah and to Him we shall return. He then said, “All praise belongs to Allah, Lord of the worlds. I pray to Allah for completion the blessings for us in you. “We are for Allah and to Him we shall return.” We asked about him and it was said that he was al-Hassan, the son of the Imam. We estimated his age at that time around twenty years or more. On that day we learned and came to know that he had tacitly made a statement about the succeeding Imam and (the Leader with Divine Authority).”