Exodus 40:7

40:7 You are to put the large basin between the tent of meeting and the altar and put water in it.

Exodus 40:30-32

40:30 Then he put the large basin between the tent of meeting and the altar and put water in it for washing. 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.