Is it permissible to take an increase in the price of prayer rugs without the knowledge of the seller and the buyer?

You are not permitted to take an increase on the price of the sheets without the permission of the woman who owns them. Rather, you must agree with her to sell them at a specific price, and anything above that is yours, or you can request a commission from the buyer. This is because taking a commission without informing the owner is considered deception and betrayal. The scholars have stated that any increase in the sale belongs to the principal, not the the agent.