The verb “to wash” (rḥṣ) ordinarily refer to the act of washing with water, but when used in the context of the tabernacle it signified inner spiritual cleansing from sin and defilement. In other words, washing with water symbolized the transformation from being ceremonially unclean to becoming ceremonially clean. According to Exodus 30:17, from this point onward, the priests had to ceremonially wash themselves every time they served in the tabernacle.
6 And Moses brought Aaron and his sons and washed them with water.