Jeremiah 33:18-22

neither shall the priests the Levites want a man before me to offer burnt-offerings, and to burn meal-offerings, and to do sacrifice continually. And the word of Jehovah came unto Jeremiah, saying, Thus saith Jehovah: If ye can break my covenant of the day, and my covenant of the night, so that there shall not be day and night in their season; then may also my covenant be broken with David my servant, that he shall not have a son to reign upon his throne; and with the Levites the priests, my ministers. As the host of heaven cannot be numbered, neither the sand of the sea measured; so will I multiply the seed of David my servant, and the Levites that minister unto me.