is it permissible to substitute books that have the words “Waqf (endowment) for the Sake of Allah” written on the cover for others bearing the same or a different title to sell them?
Waqf books are to benefit those who have them. Once they have no further use for them, they should give them to anyone who needs them. It is not permissible to sell them for money or to trade them for other books. There is nothing wrong with substituting Waqf books for other Waqf books to benefit from them, as this is not a sale. May Allah grant us success. May peace and blessings be upon our Prophet, his family, and Companions.