Exodus 40:31-33
40:31 Moses and Aaron and his sons would wash their hands and their feet from it.
40:32 Whenever they entered the tent of meeting, and whenever they approached the altar, they would wash, just as the Lord had commanded Moses.
40:33 And he set up the courtyard around the tabernacle and the altar, and put the curtain at the gate of the courtyard. So Moses finished the work.