Musannaf Ibn Abi Shayba 13:3237

Abu Bakr narrated to us, he said: Humayd ibn Abd al-Rahman narrated to us, from Muhammad ibn Muslim, from Ibrahim ibn Maysara, from Sa’id ibn Maysara, he said: There is no *’urbun* (earnest money) in *wadaq* (fat/grease), nor in fodder, nor in food, nor is there *’urbun* in anything other than them.