Exodus 40:32
When they went into the tent of the congregation, and when they came near unto the altar, they washed; as the LORD commanded Moses. When they went into the tent of the congregation, and when they came near unto the altar, they washed; as the LORD commanded Moses.
As the Lord commanded Moses, the priests washed whenever they went into the tent of meeting and whenever they came near to the altar. They washed their hands and feet at the laver. The laver stood between the altar and the congregation. That washing removed impurity, teaching that every particle of dust had to be put away before coming into God's presence.
The washing belonged to the tabernacle's sacred order and was the special preparation required before serving where God's glory was revealed. Meeting this requirement was necessary so they would not die, because God is holy. The requirement taught that those who serve God must be pure. The tabernacle's arrangements displayed God's holiness and were meant to reveal His character to the surrounding nations.