Leviticus 8:6

And washed them with water. — As the first initiatory rite of the consecration, Moses caused Aaron and his sons to bathe (see Leviticus 16:4), thus symbolising their purification from sin. Where the phrase “to wash with water” is used without specifying any particular part or parts of the body, as in Genesis 19:2; Genesis 24:32; Exodus 30:19; Exodus 30:21; Deuteronomy 21:6, it denotes the washing or bathing of the entire body. This was not done in the presence of the people, but in a baptistry, behind a curtain. During the second Temple the sacerdotal immersion could not be effected in a vessel, but had to take place in a hollow made in the ground, containing at least twenty-four cubic feet of water. The installation of the priest, which is here conducted by Moses, as the giver and representative of the Divine law, was during the second Temple performed by the Sanhedrin, who “sat in Moses’ seat.”