My father narrated to us. He said: Sa`d b. `Abdullah narrated to us. He said: Ahmad b. Abi `Abdillah al-Barqi narrated to us from his father from Khalaf b. Hammad al-Asadi from Abi’l Hasan al-`Abdi from al-A`mash from `Abaya b. Rabi`i from `Abdullah b. `Abbas from his father. He said: Abu Talib said to the Prophet (s):

O nephew! Did Allah commission you? He said: Yes. He said: Then show me a sign – he said: Call to this tree for me. So, he called to it, and it proceeded until it prostrated before him. Then, it went away. So, Abu Talib said: I bear witness that you are truthful. O `Ali, pray behind your cousin.