Charles Ellicott Commentary Exodus 29:44

"And I will sanctify the tent of meeting, and the altar: Aaron also and his sons will I sanctify, to minister to me in the priest`s office." — Exodus 29:44 (ASV)

I will sanctify also both Aaron and his sons. —Something beyond the formal consecration seems to be intended. God will continually sanctify the Levitical priesthood by the presence of His Holy Spirit with them, in their ministerial acts, and even in their daily walk, if they will seek to serve Him.