Deuteronomy 18:5
For the Lord your God has chosen them and their sons from all your tribes to stand and serve in his name permanently.
Deuteronomy 10:8
At that time the Lord set apart the tribe of Levi to carry the ark of the Lord's covenant, to stand before the Lord to serve him, and to formulate blessings in his name, as they do to this very day.
Deuteronomy 17:12
The person who pays no attention to the priest currently serving the Lord your God there, or to the verdict -- that person must die, so that you may purge evil from Israel.
Exodus 28:1-14
"And you, bring near to you your brother Aaron and his sons with him from among the Israelites, so that they may minister as my priests -- Aaron, Nadab and Abihu, Eleazar and Ithamar, Aaron's sons.
Numbers 3:10
So you are to appoint Aaron and his sons, and they will be responsible for their priesthood; but the unauthorized person who comes near must be put to death."
Numbers 16:5
Then he said to Korah and to all his company, "In the morning the Lord will make known who are his, and who is holy. He will cause that person to approach him; the person he has chosen he will cause to approach him.
Numbers 16:9-10
Does it seem too small a thing to you that the God of Israel has separated you from the community of Israel to bring you near to himself, to perform the service of the tabernacle of the Lord, and to stand before the community to minister to them?
Numbers 17:5-9
And the staff of the man whom I choose will blossom; so I will rid myself of the complaints of the Israelites, which they murmur against you."
Numbers 25:13
So it will be to him and his descendants after him a covenant of a permanent priesthood, because he has been zealous for his God, and has made atonement for the Israelites.'"