Musannaf Ibn Abi Shayba 13:2811

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Hisham al-Dastawa’i narrated to us, from al-Qasim ibn Abi Bazzah, from ‘Ata’ ibn Ya’qub, who said: Ibn ‘Umar borrowed one thousand dirhams from me, then he paid me back with dirhams better than my dirhams. He said: "Whatever excess is in them, it is a gift from me to you; will you accept it?" I said: "Yes."