Muwatta 1929

Malik says of a man who advanced dinars or dirhams for four described garments on a term. When the term fell due, he asked the debtor for them, and found he did not have them, but had other garments of the same kind that were inferior. The debtor said: I will give you eight garments from mine for them. There is no harm in that, if he takes the garments he gives before they separate. Malik said: if that term has passed it is not proper, and if it was before the term fell due, it is also not proper, unless he sells him garments that are not of the kind of the garments he advanced for. ¹

Belongs to the Muwatta, Book of Sales. Source: the Muwatta. Mentions Malik ibn Anas. Built on in the chapters on advance purchase (salaf) and riba.