سنن أبي داود

Muhammad or 'Abd Allah b. Mujahid said: 'Abd Allah b. Shaddad and Abu Burdah disputed over salaf (payment in advance). They sent me to Ibn Abi Awfa and I asked him (about it) and he replied: We used to pay in advance (salaf) during the time of the Messenger of Allah (ﷺ), Abu Bakr and 'Umar in wheat, barley, dates and raisins. Ibn Kathir added: "to those people who did not possess these things." The agreed version then goes: I then asked Ibn Abza who gave a similar reply.