Leviticus 16
4 He shall put the holy linen tunic and the linen trousers on his body; he shall be girded with a linen sash, and with the linen turban he shall be attired. These are holy garments. Therefore he shall wash his body in water, and put them on.
3 “Then Aaron shall come into the tabernacle of meeting, shall take off the linen garments which he put on when he went into the Holy Place, and shall leave them there. 24 And he shall wash his body with water in a holy place, put on his garments, come out and offer his burnt offering and the burnt offering of the people, and make atonement for himself and for the people.
The priest is to wash, then he will atone for sin. Later we see John washing in the river, the entire nation, all who will answer their call of a nation of priests. And of course those zealous for the law, but not for God (they didn't listen to Moses, as was shown to us) questioned why he was baptizing.
John 1
19 Now this is the testimony of John, when the Jews sent priests and Levites from Jerusalem to ask him, “Who are you?”
20 He confessed, and did not deny, but confessed, “I am not the Christ.”
24 Now those who were sent were from the Pharisees. 25 And they asked him, saying, “Why then do you baptize if you are not the Christ, nor Elijah, nor the Prophet?”
Water baptism is a washing. I have been washed and I have been justified. My life is hid with Christ. I don't need to be recleaned. I am dead to sin, and alive to Christ.