Is it permissible to dig a water well on the mosque's land using charity funds designated for the mosque, so that the mosque may benefit from it, and the residents of the neighborhood adjacent to the mosque may drink from it due to their need for water?

Some scholars believe it is impermissible to dig a well in a mosque except for the benefit of the worshippers and under specific conditions, because it narrows the prayer area. Digging may even be forbidden if another means of extracting water is available. "Kashshaf al-Qina" holds that digging is permissible if it serves a benefit and does not cause constriction; otherwise, it should be removed or filled. The Shafi'is have laid down conditions for the permissibility of digging a well in a mosque: that it does not narrow the prayer area, that those entering to draw water do not disturb the worshippers, and that it does not harm the mosque. If the water exceeds the needs of the worshippers, there is no harm in the general Muslim public benefiting from it.