Leviticus 9:23

Aaron, having now gone through the cycle of priestly duties connected with the brass altar, accompanies Moses into the tent of Meeting. It was reasonable that Moses, as the divinely appointed leader of the nation, should induct Aaron into the tabernacle.

Blessed the people - This joint blessing of the mediator of the Law and the high priest was the solemn conclusion of the consecration and Inauguration. (Compare 2 Chronicles 6:3.) According to one tradition, the form used by Moses and Aaron resembled Psalms 90:17. But another form is given in the Targum of Palestine, “May your offerings be accepted, and may the Lord dwell among you and forgive you your sins.”