He confirms the same thing, but by introducing a similitude; for he shews that God's covenant with the people of Israel would not be less firm than the settled order of nature. Unceasing are the progresses of the sun, moon, and stars; continual is the succession of day and night. This settled state of things is so fixed, that in so great and so multiplied a variety there is no change. We have now rain, then fair weather, and we have various changes in the seasons; but the sun still continues its daily course, the moon is new every month, and the revolving of day and night, which God has appointed, never ceases; and this unbroken order declares, as it is said in Psalm 19, the wonderful wisdom of God. The Prophet then sets before us here the order of nature, and says, that God's covenant with his Church shall be no less fixed and unchangeable than what it is with mankind, with regard to the government of the world. We now perceive the purpose of the Prophet in saying, If void ye can make my covenant respecting the day and the night, then abolished shall be my covenant with David and the Levites Now he indirectly touches on the wickedness of the people; for the Jews did, as far as they could, overthrow, by their murmurs and complaints, the covenant of God; for in their adversities they instantly entertained the thought and also expressed it, that God had forgotten his covenant. This want of faith then is intimated by the Prophet, as though he had said, "Why are these complaints? It is the same thing as though ye sought to pull down the sun and the moon from the heavens, and to subvert the difference between day and night, and to upset the whole order of nature; for I am the same God, who has settled the succession of day and night, and has promised that the Church shall continue for ever: ye can, therefore, no more abolish my covenant with David than the general law of nature." We now then understand the Prophet's object: for this was not said without conveying reproof; because they were very wicked and ungrateful to God, when they doubted his truth and constancy, respecting the promise as to the perpetual condition of the Church. He in short intimates that they were carried away, as it were, by a blind madness, when they thus hesitated to believe God's covenant, as though they attempted to subvert the whole world, so that there should be no longer any difference between light and darkness. Hence he says, There shall be abolished my covenant with David my servant, that he should not be my son, etc. He repeats what he had said, even that it could not be but that the posterity of David should obtain the kingdom, which we know has been fulfilled in Christ. The throne of David he now calls what he had named before as the throne of the house of Israel; but he means the same thing. It is called the throne of the house of Israel, because the king and the people are relatively connected, and also because the posterity of David ruled for the public good, not for their own sake. He adds, and with the Levites, the priests, my ministers He had called David his servant, he now calls the Levites his ministers. The word srt sheret, is commonly known, and is used often by Moses, when speaking of the Levitical priesthood. Its meaning is to serve. He adds --

And the word of the Lord came unto Jeremiah,.... For the further explanation and confirmation of what is before said; and which came at the same time as the other; this being not a new prophecy, but an illustration of the former:
saying; as follows: