The World Federation One Stop Fiqh

Ruling 268

If someone does not want to perform prayers in a mosque and does not know whether the mosque’s pool is a charitable endowment to the general public or only to those who perform prayers in the mosque, he cannot perform wuḍūʾ with water from the pool of the mosque. However, if people who also do not usually pray in that mosque perform wuḍūʾ with water from that pool and no one prohibits them from doing so, one can perform wuḍūʾ with it.