Is it permissible to sell an antique book containing Christian beliefs, even though neither the seller nor the buyer is selling a creed? And is it obligatory to inform the original owner of its true value after learning it?

Scholars have differed concerning the right of the defrauded party to return a sale. Imam Malik held that the sale proceeds and the defrauded party does not have the right to revoke it. As for selling books that contain errant doctrines, it is permissible to sell them to Muslim specialists who utilize them to refute the people of misguidance. It is disliked for one to acquire them merely for perusal, and it is forbidden to sell them to the general public or to those who would use them for falsehood.