John Calvin Commentary Jeremiah 23:40

"and I will bring an everlasting reproach upon you, and a perpetual shame, which shall not be forgotten." — Jeremiah 23:40 (ASV)

What is contained here is that, although the Jews justly gloried for a time in being God's chosen people, this would be of no use to them, as they had stripped themselves of that honor in which they had excelled by the rejection of true religion. Here, then, the Prophet strips the Jews of that foolish boasting with which they were puffed up when they said that they were the people of God, and threatens that God, having taken away their glory, would make them endure perpetual shame.

We also know that such threats are limited in time; they extend only until the coming of Christ, for the Church of God could not have been doomed to eternal reproach. But as for hypocrites, since there was no repentance, they never obtained pardon; but God delivered His own from eternal reproach when Christ the Redeemer appeared; yet these words are to be understood as rightly addressed to the ungodly despisers of God.