Is it permissible to buy an item with the intention of helping the poor seller, then return the amount and give him a larger amount as charity, while making the increase for him?

It is permissible to buy goods from a poor seller for more than their real price, and this is considered a hidden charity, taking into account the feelings of the needy, based on the saying of the Prophet, peace and blessings be upon him: "A man who gives charity and conceals it so much that his left hand does not know what his right hand has spent." Al-Qurtubi said that this act is an exaggeration in concealing charity, and it is done by paying the weak person in the guise of buying from him.