Muwatta 1971

Malik says of a man who buys food and measures it out, then another comes to buy it from him, and he tells the newcomer that he measured it out for himself and received it in full. The buyer wants to believe him and take it by his measure. If it is sold this way for cash, there is no harm. If sold this way on a term, it is disliked until the second buyer measures it for himself. It was disliked on a term because it is a means to riba, and there is fear that it might be passed around in this way without measure or weight. ¹

Belongs to the Muwatta, Book of Sales. Source: the Muwatta. Mentions Malik ibn Anas. Built on in the chapters on sale and riba.