Another example of Imam Musa's immoderate cleverness is that he came to his father carrying a tablet (lawh) with him. His father made him sit in his lap and said to him: "My little son, write: Abandon ugly things and do not perform them!" When he wrote that, his father said to him: "My little son, complete it." He completed it saying: "If you perform good deeds to someone, then increase them." Then the Imam gave another statement to his son and ordered him to complete it, saying: "You will meet from your enemy all tricks." He completed it saying: "If the enemy schemes against you, do not scheme against him." The Imam became happy with his son' talents and genius; he embraced him, showed his admiration toward him, and said: "Offspring, one of the other!" Another example of the sings of his genius in his childhood is that which has been reported by Saffwan al-Jammal, who said: "I (Saffwan al-Jammal) asked Abu 'Abd Allah (al-Sadiq), peace be on him, about the leader of this affair (after him). He said: 'The leader of this affair is one who does not fool and play.'"
Saffwan said: "While he was relating to me about that, Abu al-Hasan Musa, who was then a young boy, came towards us along with a young sheep. He addressed the young sheep, saying: 'Prostrate to your Lord!' So Abu 'Abd Allah, peace be on him, took and embraced him, and then he said to him: 'May my father and mother be ransom to you, O you who do not fool and play!'"