Forgotten and forsaken are much the same thing, differing only as the cause and the effect; for if men remembered God as they ought to do, they would not forsake him. By vanity he means idols; which are called vanity, not only because they are in themselves nothing of what they are pretended to be, and because the worshipping of them is a high degree of sin, which is often called vanity in Scripture, but because the service of them is of no use nor profit, or advantage; and any expectations from them are idle and vain, for which there is no ground at all. Whether the false prophets or the idols are here said to cause them to stumble by receding from the ancient paths is uncertain. The words may either be translated paths of eternity, or paths of antiquity; the most and best translate it as we do. Quid veturn primurn, The ways of truth are the most ancient ways; the ways wherein Noah, Abraham, Isaac, and Jacob, and all the ancient patriarchs did walk. To walk in paths, or in a way not cast up, not fitting for God's people to walk in. Proverbs 15:19, The way of the righteous is said to be a way made plain, Heb. raised up as a causey. Wicked men, in opposition to these ways, are said to walk in a way not cast up.
Related Commentaries of Jeremiah 18:15
Jeremiah 18:15
15 Because my people hath forgotten me, they have burned incense to vanity, and they have caused them to stumble in their ways from the ancient paths, to walk in paths, in a way not cast up;