Musnad Ahmad 1720

It was narrated that ‘Amr bin Hubshi said: al-Hasan bin "Ali addressed us after "Ali (رضي الله عنه) was killed. He said: A man left you yesterday whom none of the early ones surpassed in knowledge and none of the latter ones will ever catch up with him. The Messenger of Allah (ﷺ) would send him and give him the banner, and he would not give up until victory had been granted to him. He did not leave behind any yellow or white (i.e., gold or silver) except seven hundred dirhams of his stipend that he was keeping to buy a servant for his family.