Musannaf Ibn Abi Shayba 13:1060

Abu Bakr narrated to us, he said: Yahya bin Sa'id al-Qattan narrated to us, from Ibn Harmala, who said: I sold a camel for dirhams [to be paid] at the time of harvest. When it became due, they paid me in wheat, barley, and *sult* (a type of barley). I asked Sa'id bin al-Musayyib, and he said: "It is not permissible; do not take anything except the dirhams."