Is it permissible for a shop owner who has been given money to donate it as charity to take goods from his shop equivalent to the value of that money and donate them, and would he be credited with the profit from selling these goods or their original value?

In this case, the shop owner is an agent for the giver of charity. The default is that the amount should be given as cash charity, just as the giver provided it. He should not buy items with it to give as charity to the poor. This requires a specific permission for purchase, or for it to be common practice and established by custom; because an agent only has the authority to act in ways necessitated by the principal's permission, whether explicitly stated or understood through custom.

If the principal permits the purchase of items to be distributed to the poor, then it is not permissible for the agent to buy from himself except with the principal's knowledge and permission, though there is a difference of opinion among scholars on this matter. According to the Hanafis, Malikis, and Hanbalis, it is not permissible for an agent to buy from himself for the principal, even if the principal permits it, due to the suspicion of the agent and the convergence of two conflicting interests. An exception to this is if the principal permits the agent to buy from what the agent owns, in which case they permitted it because the suspicion is removed.

According to the Shafi'is, an agent should not buy for his principal from what the agent or his relatives own, even if permitted, because the general rule is that the offeror and acceptor should not be the same. Therefore, it is not permissible for the shop owner to buy from himself unless his principal permits him to do so, and in this case, he must buy at the market price without favoring himself.