Muhammad or `Abdullah bin Abu Al-Mujalid said, "Abdullah bin Shaddad and Abu Burda differed regarding As-Salam, so they sent me to Ibn Abi `Aufa and I asked him about it. He replied, 'In the lifetime of Allah's Messenger (ﷺ), Abu Bakr and `Umar, we used to pay in advance the prices of wheat, barley, dried grapes and dates to be delivered later. I also asked Ibn Abza and he, too, replied as above.' "
Sahih al-Bukhari Book 35, Hadith 6
← Previous Hadith The Prophet (ﷺ) came (to Medina) and he told the people (regarding the payment of money in advance that they should pay it) for a known specified measure and a known specified weight and a known specified period.

Sahih al-Bukhari Book 35, Hadith 5 Next Hadith → `Abdullah bin Shaddad and Abu Burda sent me to `Abdullah bin Abi `Aufa and told me to ask `Abdullah whether the people in the lifetime of the Prophet (ﷺ) used to pay in advance for wheat (to be delivered later). `Abdullah replied, "We used to pay in advance to the peasants of Sham for wheat, barley and olive oil of a known specified measure to be delivered in a specified period." I asked (him), "Was the price paid (in advance) to those who had the things to be delivered later?" `Abdullah bin `Aufa replied, "We did not use to ask them about that." Then they sent me to `Abdur Rahman bin Abza and I asked him. He replied, "The companions of the Prophet (ﷺ) used to practice Salam in the lifetime of the Prophet; and we did not use to ask them whether they had standing crops or not."

Sahih al-Bukhari Book 35, Hadith 7