2 Chronicles 13:10

But as for us, the Lord is our God, and we have not been turned away from him; we have priests who do the work of the Lord, even the sons of Aaron and the Levites in their places;

Exodus 19:5-6

If now you will truly give ear to my voice and keep my agreement, you will be my special property out of all the peoples: for all the earth is mine:

Exodus 29:1-37

This is what you are to do to make them holy, to do the work of priests to me: Take one young ox and two male sheep, without any mark on them,

Numbers 16:40

To be a sign, kept in memory for ever by the children of Israel, that no man who is not of the seed of Aaron has the right of burning spices before the Lord, so that he may not be like Korah and his band: as the Lord said to him by the mouth of Moses.

Numbers 18:1-7

And the Lord said to Aaron, You and your sons and your father's family are to be responsible for all wrongdoing in relation to the holy place: and you and your sons are to be responsible for the errors which come about in your work as priests.

2 Chronicles 11:16-17

And after them, from all the tribes of Israel, all those whose hearts were fixed and true to the Lord, the God of Israel, came to Jerusalem to make offerings to the Lord, the God of their fathers.

Zechariah 13:9

And I will make the third part go through the fire, cleaning them as silver is made clean, and testing them as gold is tested: and they will make their prayer to me and I will give them an answer: I will say, It is my people; and they will say, The Lord is my God.

Treasury of Scripture Knowledge

Summary

But as for us, the LORD is our God, and we have not forsaken him; and the priests, which minister unto the LORD, are the sons of Aaron, and the Levites wait upon their business:

Bible References

The lord

2 Chronicles 11:16
And after them, from all the tribes of Israel, all those whose hearts were fixed and true to the Lord, the God of Israel, came to Jerusalem to make offerings to the Lord, the God of their fathers.
Exodus 19:5
If now you will truly give ear to my voice and keep my agreement, you will be my special property out of all the peoples: for all the earth is mine:
Zechariah 13:9
And I will make the third part go through the fire, cleaning them as silver is made clean, and testing them as gold is tested: and they will make their prayer to me and I will give them an answer: I will say, It is my people; and they will say, The Lord is my God.

The priests

Exodus 29:1
This is what you are to do to make them holy, to do the work of priests to me: Take one young ox and two male sheep, without any mark on them,
Numbers 16:40
To be a sign, kept in memory for ever by the children of Israel, that no man who is not of the seed of Aaron has the right of burning spices before the Lord, so that he may not be like Korah and his band: as the Lord said to him by the mouth of Moses.
Numbers 18:1
And the Lord said to Aaron, You and your sons and your father's family are to be responsible for all wrongdoing in relation to the holy place: and you and your sons are to be responsible for the errors which come about in your work as priests.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain