question #1 Sahih al-Bukhari 2245, Book 35, Hadith 8 : What is the practice of paying in advance for goods in Islamic trade?

as above (446) and said, “We used to pay them in advance for wheat and barley (to be delivered later).
Narrated Ash-Shaibani–“And also for oil.”Narrated Ash-Shaibani:who said “We used to pay in advance for wheat barley and dried grapes.”