Musannaf Ibn Abi Shayba 13:2052

Abu Bakr narrated to us, he said: Ibn Idris narrated to us, from Husayn, from al-Sha’bi, who said: ‘Abdullah ibn Yazid al-Ansari gave four thousand to a slave of his. He went to Isfahan and traded until it became twenty thousand. Then he died. It was said to him [‘Abdullah], "He was approaching usury." So he took the four thousand and left what was besides that.