What is the ruling on allocating a space from the endowment (waqf) belonging to the mosque to build a house that supplies the neighborhood and the mosque with electricity, and is it permissible to dispose of an endowment in this manner for a public interest?

It is permissible to use the unused shops belonging to the mosque for the benefit of the mosque or the neighborhood if those in charge of the mosque deem it to be in the public interest and the mosque does not need those shops. Therefore, spending surplus money beyond the mosque's needs on other mosques or other public interests is permissible. Sheikh Taqi al-Din mentioned that it is permissible to spend the surplus on similar matters and on all other public interests.