John Calvin Commentary Jeremiah 6:21

"Therefore thus saith Jehovah, Behold, I will lay stumbling-blocks before this people; and the fathers and the sons together shall stumble against them; the neighbor and his friend shall perish." — Jeremiah 6:21 (ASV)

Here God, in plain words, declares what vengeance He would execute on the people. He says first, that He would lay for them stumbling blocks. He no doubt compares the judgments which were near to nets or traps, for the Jews hoped to escape. He therefore says that they would be ensnared: “Wherever you go,” He says, “you will meet with those nets by which God will catch you: Fall, therefore, shall both fathers and sons, the neighbor and his friend.”

He means by these words that however they might conspire together, they would yet be exposed to the same punishment. For when sons follow the examples of their fathers, they think themselves innocent; and also, when anyone has many associates, he thinks himself safe in his licentiousness. Since, then, consent or society hardens the ungodly, so that they do not fear the wrath of God, the Prophet on this account includes sons with their fathers, and a neighbor with his friend, as those who were to perish together and without any difference. The word “stumbling blocks” is indeed metaphorical; but in the next verse the Prophet speaks without a figure and says—