Numbers 3:10
And you shall appoint Aaron and his sons, and they shall wait on their priest's office: and the stranger that comes near shall be put to death.
Torrey's Topical Textbook—AKJV

Numbers 18:1,2
And the LORD said to Aaron, You and your sons and your father's house with you shall bear the iniquity of the sanctuary: and you and your sons with you shall bear the iniquity of your priesthood.
Torrey's Topical Textbook—AKJV

Hebrews 9:6
Now when these things were thus ordained, the priests went always into the first tabernacle, accomplishing the service of God.
Torrey's Topical Textbook—AKJV