The Torah describes ablutions for the priests and for others...

The Torah describes ablutions for the priests and for others on certain occasions of ritual defilement, such as contact with the dead and sexual activity. Exodus 29:4. `And Aaron and his sons thou shalt bring unto the door of the tabernacle of the congregation, and shalt wash them with water.' See also Exodus 40:12, Leviticus 8:6. Exodus 30:18-21.

'Thou shalt also make a laver of brass, and his foot also of brass, to wash withal: and thou shalt put it between the tabernacle of the congregation and the altar, and thou shalt put water therein.

For Aaron and his sons shall wash their hands and their feet thereat: When they go into the tabernacle of the congregation, they shall wash with water, that they die not; or when they come near to the altar to minister, to burn offering made by fire unto the Lord: So they shall wash their hands and their feet, that they die not: and it shall be a statute for ever to them, even to him and to his seed throughout their generations.' See also Exodus 30:30-32. Leviticus 14:9.

`But it shall be on the seventh day, that he shall shave all his hair off his head and his beard and his eyebrows, even all his hair he shall shave off. and he shall wash his clothes, also he shall wash his flesh in water, and he shall be clean.' See also Leviticus 15:5-11,13,16,17,21, 22,27. Numbers 19:7-8. `Then the priest shall wash his clothes, and he shall bathe his flesh in water, and afterward he shall come into the camp, and the priest shall be unclean until the even.

And he that burneth her shall wash his clothes in water, and bathe his flesh in water, and shall be unclean until the even.' See also verses 18-19. Deuteronomy 23:11. `But it shall be, when evening cometh on, he shall wash himself with water; and when the sun is down, he shall come into the camp again.' The prophets note some instances of ablution, in some cases showing slight differences in the details from those depicted in the Torah. 2 Kings 5:10,14.

`And Elisha sent a messenger unto him, saying, Go and wash in Jordan seven times, and thy flesh shall come again to thee, and thou shalt be clean... Then he went down, and dipped himself seven times in Jordan, according to the saying of the man of God: and his flesh came again like unto the flesh of a little child, and he was clean.' 2 Chronicles 4:6.