Jeremiah 33:17-21

17For this is what the Lord says: ‘David will never fail to have a man to sit on the throne of Israel, 18nor will the Levitical priests ever fail to have a man to stand before me continually to offer burnt offerings, to burn grain offerings and to present sacrifices.’ ” 19The word of the Lord came to Jeremiah: 20“This is what the Lord says: ‘If you can break my covenant with the day and my covenant with the night, so that day and night no longer come at their appointed time, 21then my covenant with David my servant—and my covenant with the Levites who are priests ministering before me—can be broken and David will no longer have a descendant to reign on his throne.