Narrated Muhammad ibn al-Muthanna: Yahya ibn Sa'id narrated to us from Shu'bah. And it was also narrated by 'Amr ibn 'Ali: Yahya ibn Sa'id and 'Abd al-Rahman ibn Mahdi narrated to us, both saying: Shu'bah narrated to us from Qatadah, from Abu al-Khalil, from 'Abdullah ibn al-Harith, from Hakim ibn Hizam, from the Prophet (peace be upon him), who said: "The two parties to a sale have the option [to cancel it] as long as they have not separated. If they are truthful and make things clear, they will be blessed in their transaction, but if they lie and conceal, the blessing of their transaction will be erased."