“I once heard al-Rida’ (a.s.), saying, ‘The choice to revoke a contract of sale in the case of animals is for three days in favor of the buyer and in non-animal it is as long as they have not departed each other. The happenings of the year are returned after the year.’ I asked, ‘What is happening of the year?’ He (the Imam) said, ‘They are madness and leprosy, Bars (leprosy), and al-Qarn. One who buys and some of these things happen, then the rule is that it is returned to the owner up until the end of the year from the day of purchase.’”