Exodus 29:30, 35, 37

Aaron’s son, who will become high priest after Aaron, will come to the Meeting Tent to serve in the Holy Place. He is to wear these clothes for seven days.

“Do all these things that I commanded you to do to Aaron and his sons, and spend seven days appointing them.

Spend seven days making the altar ready for service to God and making it holy. Then the altar will become very holy, and anything that touches it must be holy.