Musannaf Ibn Abi Shayba 13:457

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mughira, he said: I asked Ibrahim about a man who sold a sheep to a man, then it occurred to him [to cancel the sale] before he had taken it, so he said, "Cancel the sale for me," but he refused and said, "Give me a dirham and I will cancel the sale for you." He disliked that.