Musannaf Ibn Abi Shayba 13:794

Abu Bakr narrated to us, he said: Yahya bin Sa'id al-Qattan narrated to us, from Muhammad bin Abdullah bin Abi Maryam, who said: I said to Sa'id bin al-Musayyib: "I sold dates to a man; may I take dates in exchange for the price of my dates?" He said: "Do not take food that is measured or weighed."