A man who sells a debt for a deferred term

Ibrahim was asked about a person who made a sale for a fixed term, and the buyer then sold it to a man: may the one who first sold it buy it? He said: If there is no loss to him in it, there is no harm.

Al-Hasan said about this: If there is no loss in it, there is no harm.

It is narrated from Dawud bin Abi Asim that he sold something to his sister for a fixed term, then she ordered him to sell it, and he sold it. I asked Sa'id bin al-Musayyib about it. He said: See, are you that very person? I said: Yes, I am he. He said: That is usury (riba), it is usury; so take back from her only your capital.