Exodus 19:22

19:22 Let the priests also, who approach the Lord, sanctify themselves, lest the Lord break through against them.”

Exodus 30:29-30

30:29 So you are to sanctify them, and they will be most holy; anything that touches them will be holy.

30:30 “You are to anoint Aaron and his sons and sanctify them, so that they may minister as my priests.