The Jews washed their feet upon entry into the house because they were walking on muddy or dusty ground. They washed hands before and in between each course of meal and cleaned all the utensils carefully with water as a ceremonial custom. There were other ceremonial washings for Israelites in the Old Testament, including immersion in water.
Israelites had had cleansing ceremonies like the baptism of John. Before the ordination to priesthood, Moses washed Aaron and his sons with water as per the directive of God through Moses (Lev 8:6). On the Day of Atonement, Aaron had to bathe his body in water before he robed his vestments to enter the Holy of Holies (Lev 16:4). Those who have touched a human corpse were unclean for seven days and they had to purify themselves with water on the third and seventh day as part of their ritual purification (Num19:11-12). The new converts to Judaism had to undergo immersion in water known as Mikveh which was symbolic of transition from his or her old identity to a new one as a Jew.
Along with physical cleansing, spiritual cleansing is important. Jesus criticized the Pharisees: “Oh you Pharisees! Although you cleanse the outside of the cup and the dish, inside you are filled with plunder and evil” (Lk 11:39). “From the heart come evil thoughts, murder, adultery, unchastity, theft, false witness, blasphemy. These are what defile a person, but to eat with unwashed hands does not defile” (Mt 15:9-20). Are our hearts defile or holy?