Musannaf Ibn Abi Shayba 33:921

'Affan ibn Muslim narrated to us, he said: Ja'far ibn Sulayman narrated to us, he said: One of our companions narrated to us, he said: Mawraq al-'Ijli used to trade and acquire wealth, and a Friday would not pass while he still had any of it left. He said: He would meet a brother from among his brothers and give him four hundred, five hundred, or three hundred [dirhams], and say: "Keep it for us with you until we need it." Then he would meet him after that and say: "It is yours to do with as you please." The other would say: "I have no need for it." He would then say: "By Allah, we will never take it back; it is yours to do with as you please."