“I once purchased a carriage and paid a certain amount of the price, then left it with the seller. I remained engaged for several days then went to the seller to take possession. He said, ‘I have sold it.’ I laughed and said, ‘By Allah, I will not allow you to do this without asking for a judgment.’ He said, ‘Will you agree to go for judgment before abu Bakr ibn ‘Ayyash?’ I replied, ‘Yes, I agree.’ We went to him and told him about our stories. Abu Bakr asked, ‘On the basis of whose words you want me to decide?’ He (the narrator) has said that I asked him to decide on the basis of the words of my companion (Imam).’ He said, ‘I heard him (Imam) say, “If one brings payment within three days the deal is valid, otherwise, there is no deal in his favor.’”