Sayyiduna Malik bin Aws (may Allah be pleased with him) narrates: I went out with one hundred dinars. I met Sayyiduna Talhah bin Ubaidullah (may Allah be pleased with him), who was sitting in the shade of a wall. He agreed on the price with me and said that when his servant would come from Ghabah, he would make the payment. Sayyiduna Umar (may Allah be pleased with him) heard this. He inquired about it from Sayyiduna Talhah (may Allah be pleased with him), so he explained: There are some dinars (which I am buying), and I intend that when my servant comes from Ghabah, (then I will make the payment). Sayyiduna Umar (may Allah be pleased with him) said: Do not separate from him, do not separate from him until you have paid him. The Prophet (peace and blessings of Allah be upon him) said: Exchanging gold for silver is usury, except when it is hand to hand; exchanging wheat for wheat is usury, except when it is hand to hand; exchanging barley for barley is usury, except when it is hand to hand; exchanging dates for dates is usury, except when it is hand to hand.