Musnad Ahmad 16:3

Waki’ narrated to us, from Isra’il, from Abu Ishaq, from ‘Amr ibn Hubshi, who said: Al-Hasan ibn ‘Ali delivered a sermon to us after the killing of ‘Ali, may Allah be pleased with them both, and said: "A man has departed from you yesterday whom the predecessors did not surpass in knowledge, nor will the successors reach. The Messenger of Allah, peace and blessings of Allah be upon him, used to send him and give him the banner, and he would not return until it was opened for him. He did not leave behind any gold or silver, except for seven hundred dirhams from his stipend, which he was saving for a servant for his family."