Musannaf Ibn Abi Shayba 13:1623

Abu Bakr narrated to us, he said: Muhammad ibn Fudayl narrated to us, from Bukayr ibn Atiq, from Sa’id ibn Jubayr, that he used to dislike the sale of "ten for twelve and ten for twelve." I said to him: "Then how should I do it?" He said: "Say: 'I took it for such-and-such, and I sell it to you for such-and-such.'"