Qutaybah ibn Sa'id narrated to us, saying: Layth narrated to us. And (another chain) Muhammad ibn Rumh narrated to us, saying: al-Layth informed us, from Nafi', from Ibn 'Umar, from the Messenger of Allah, peace and blessings be upon him, that he said: "When two men engage in a sale, each of them has the option [to cancel] as long as they have not separated and they are both together, or one of them gives the other the choice. If one of them gives the other the choice, and they conclude the sale on that basis, then the sale is binding. And if they separate after concluding the sale and neither of them has rescinded the sale, then the sale is binding."