There is nothing wrong with telling the customers about painters in return for money that you take from the painter whenever a customer comes to him through you, whether that payment is a set amount or a percentage. This is what is called a broker’s or agent’s fee. It says in Fataawa al-Lajnah al-Daa’imah (13/131): It is permissible for the agent to accept a fee of a known percentage of the final agreed price of the product in return for telling the customer about it, and he may take it [that fee] from the buyer or the seller, according to the agreement, without any being unfair or causing any harm.
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