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).