It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The seller and the buyer have the option (to cancel the transaction) as long as they do not separate, or if it is a sale with an option (of rescinding)." Nafi' would sometimes say: or if one of them says to the other, 'Make your choice.'"