He replied:

As for a sale with a repurchase agreement—whereby the parties agree that, whenever the seller brings back the price, the purchaser will restore his property to him, while the purchaser benefits from it by letting it, living in it, or otherwise—such a sale is invalid by scholarly consensus if the condition forms part of the contract.

If the condition was stipulated before the contract and its validity is disputed, the correct view is that the sale is invalid in all cases. The parties’ sole purpose is to engage in usury by advancing dirhams for a fixed term, with the benefit obtained in return for those dirhams constituting the profit. The property sold must be returned to its owner, the seller, and the seller must repay the purchaser what he received from him. However, any money the purchaser received under the name of rent must be deducted from the amount the seller owes him. And Allah knows best.

He was also asked:

An enslaved man buys and sells for his master, and his master buys and sells in the slave’s name. The master has incurred a debt. Should repayment be sought from the slave or from his owner?

He replied:

Praise be to Allah. The debt is the master’s responsibility and must be paid from his wealth. Whatever the slave holds belongs to the master and must be used to repay his debt. The slave may also be sold to repay his master’s debt. If the slave conceals any of his master’s wealth that is in his possession, he is to be punished until he discloses it, so that the debt may be repaid from it. And Allah knows best.