AARON WASHED HIMSELF IN WATER

In order to appear before the God of Israel in the Holy of Holies, Aaron needed to wash himself in water.

Leviticus 16:3 Thus shall Aaron come into the holy place ...

Leviticus 16:4 He shall put on the holy linen coat and he shall have the linen breeches upon his flesh and shall be girded with a linen girdle and with the linen mitre shall he be attired: these are holy garments; therefore shall he wash his flesh in water and so put them on.