Muwatta 1951

Yahya said Malik said: the agreed practice among us about cloth which a man buys in one city, then brings to another city and sells on a cost-plus basis, is that the broker's fee is not counted, nor the cost of folding or binding, nor the expense, nor the rent of a room. The hire of carrying the cloth is counted in the principal price, and no profit is counted on it, unless the seller knows the buyer will bargain on all of it, and if they profit on all of it after knowing it, there is no harm in it. ¹

Belongs to the Muwatta, Book of Sales. Source: the Muwatta. Mentions Yahya ibn Yahya al-Laythi, Malik ibn Anas. Built on in the chapters on resale at cost plus profit (murabaha).