Narrated Ibn Abi Awfa (may Allah be pleased with him): "We used to practice Salam (advance payment sale) in wheat, barley, grapes, and dates during the time of the Messenger of Allah (peace and blessings of Allah be upon him), Abu Bakr As-Siddiq (may Allah be pleased with him), and Umar Farooq (may Allah be pleased with him)."

Narrated Sayyiduna Ibn Abi Awfa (may Allah be pleased with him):
We used to do salam (forward contract) with the farmers of Syria for wheat, barley, and olives for a specified measure and a specified period. It was asked whether you used to do this transaction with those who possessed the actual goods. Sayyiduna Ibn Abi Awfa (may Allah be pleased with him) replied: We did not use to ask them (whether they had the actual goods or not).