'Priests and Levites' in the Bible

David said to all the assembly of Israel, "If it seems good to you, and if it is of Yahweh our God, let us send abroad everywhere to our brothers who are left in all the land of Israel, with whom the priests and Levites are in their cities that have suburbs, that they may gather themselves to us;

They didn't depart from the commandment of the king to the priests and Levites concerning any matter, or concerning the treasures.

But many of the priests and Levites and heads of fathers' [houses], the old men who had seen the first house, when the foundation of this house was laid before their eyes, wept with a loud voice; and many shouted aloud for joy:

Also we inform you, that touching any of the priests and Levites, the singers, porters, Nethinim, or servants of this house of God, it shall not be lawful to impose tribute, custom, or toll, on them.

On that day were men appointed over the rooms for the treasures, for the wave offerings, for the first fruits, and for the tithes, to gather into them, according to the fields of the cities, the portions appointed by the law for the priests and Levites: for Judah rejoiced for the priests and for the Levites who waited.

This is John's testimony, when the Jews sent priests and Levites from Jerusalem to ask him, "Who are you?"