Mālik ibn Aws ibn al-Hadathān reported: I came saying: Who will exchange the dirhams? Talhah ibn ‘Ubaydullāh, who was in the company of ‘Umar ibn al-Khattāb (may Allah be pleased with both of them), said: Show us your gold, then come to us when our servant comes to give you your silver. Thereupon, ‘Umar ibn al-Khattāb said: No, by Allah, you must either give him his silver or give him back his gold, as the Messenger of Allah (may Allah's peace and blessings be upon him) said: "Silver for gold is Riba (usury) unless exchanged on the spot; wheat for wheat is Riba unless exchanged on the spot; barley for barley is Riba unless exchanged on the spot; and dates for dates is Riba unless exchanged on the spot."