The first people who saw you…
Forty men of Shiites who had credibility gathered at Imam Askari’s home to ask about the next Imam. Othman ibn Sa'id stood up and said, "O Son of the Messenger of Allah! I want to ask you about something, you are more knowledgeable about it." Imam said, "O Othman! Sit down." Othman was upset and wanted to leave, Imam said:" No one should leave." And no one did so, after a moment, Imam called Othman and said, " I tell you that what you came for?" They said, "O Son of Messenger of Allah!" He said, "You have come here to ask me about the next Imam after me?" they said "yes" at this time a "boy" who was like the moon came in.
Imam Askari said, “After me this boy is your Imam and my successor. "obey him” and "do not disperse" after me because you will perish in your religion.”
Milad, the collection of articles, p.51