What is the reward for building a washing facility for the deceased?

Washing the deceased Muslim is a communal obligation (fard kifaya). Building a washing facility for deceased Muslims helps fulfill this obligation and is considered a good deed, a perpetual charity (sadaqah jariyah) from which its giver benefits after death. This is based on the Prophet's (peace be upon him) saying: "When a person dies, all his deeds come to an end except for three: an ongoing charity, beneficial knowledge, or a righteous child who prays for him." It is advisable that someone with religious knowledge of washing and shrouding the deceased supervises it.