Musannaf Ibn Abi Shayba 13:798

Abu Bakr narrated to us, he said: Abda bin Sulayman narrated to us, from Sa’id, from Qatada, from Tawus, who said: Ibn Abbas said: "If you sell a sale of that which is measured or weighed for a fixed term, and your term becomes due, then do not take anything other than what you found, for it contradicts both of them."