“‘Umar and I were in al-Madinah and ‘Umar sold sacks made in Hirat, every cloth for so and so amount. They took them and divided among themselves but they found one defective piece and returned it. ‘Umar said to them, ‘I can pay you the price for which I sold to you.’ He said, ‘No, we take from you the price of the cloth.’ ‘Umar mentioned this before abu ‘Abd Allah (a.s.), and he (the Imam) said, ‘He must do so (as he is asked to do).”’ (The pronoun ‘He’ can apply to either one of seller or buyer but its applying to the buyer has greater support in the principles of the system of Shari ‘ah)