Muwatta 1840

Malik says: what makes the difference is taking possession. Whoever takes possession of what he hired or rented has left the uncertainty and the disliked advance, and taken a known thing. The likeness is that a man buys a slave or a slave-girl, takes possession of them and pays their prices; if an event happens during the warranty year, he takes his gold back from the seller who sold to him. This is no harm, and the practice in the sale of slaves has gone this way. 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 warranty.