The practice of ritual washing in a religious rite to cleanse a person of sin or disease, to purify, or to signify humility or service to others. In Christianity, baptism and foot-washing are both forms of ablution. In liturgical churches, ablution can refer to purifying fingers or vessels related to the Eucharist. In Islam, ablution is ritual washing, known as wudu, before prayer. In Judaism, immersion in a mikvah is a form of ablution.