Section
The permissible cases are distinguished from the invalid ones by two criteria: first, buying back more food than was sold; and second, buying back at a lower price than that for which the food was sold. Neither is permissible for cash, but both are permissible by offsetting the debts if the buyer has not taken the food away. If he has taken it away, neither is permissible, whether for cash or by offsetting.
The seller may not buy back his food together with anything additional at the same price, a higher price, or a lower price for cash, even if the buyer has not taken the food away. If he has taken it away, this is impermissible both for cash and by offsetting. Nor may the seller buy back the very food he sold, any part of it, or that food together with an additional quantity, at a lower price for cash, even if the buyer has not taken it away; if he has taken it away, this is impermissible both for cash and by offsetting.
All the other cases are permissible, both for cash and by offsetting, except for the case already mentioned as permissible according to a disputed opinion: buying back a smaller quantity of food at the same price by offsetting the debts. Mālik—may Allah Most High have mercy on him—gave differing opinions on this.
Section
Of the eighteen cases involving repurchase with payment deferred beyond the original due date, thirteen are impermissible by agreement, one is permissible according to a disputed opinion, and the remaining four are permissible by agreement. Here too, the permissible cases are distinguished from the invalid ones by two criteria: (first), buying back a smaller measured quantity; and (second), buying back at a higher price. Neither is permissible, whether or not the buyer has taken the food away.
All the other cases are permissible if the buyer has not taken the food away, but impermissible if he has, except for the disputed case: buying it back from him after he has taken it away, at the same price, with payment deferred beyond the original due date. This is permissible according to Ibn al-Qāsim’s position, but not according to Ibn al-Mājishūn’s. The underlying issue is, “Lend to me, and I will lend to you,” since that is what their dealings ultimately amount to. Ibn al-Mājishūn therefore disapproved of it and did not permit it, whereas Ibn al-Qāsim took a more lenient view and did not suspect the two parties of intending such an arrangement.