John Calvin's Bible Commentary
Jeremiah 11:9
Here the Prophet joins closer battle with the men of his age, and says, that they were worse than their fathers; for this is the meaning of the word, banding or joining together. For when the Israelites concurred in a body in ungodly superstitions, it was more excusable at the beginning, for they had not yet struck deep roots in true religion; but when God by his prophets had endeavored many times, and in various ways, to restore them to the right way, and when his diligence and assiduous efforts had proved fruitless, it was an evidence of confirmed and hopeless obstinacy. He then says, that this had been discovered; for this is what he means by saying, that it had been found out This verb is often used in Scripture in another sense, but it means here the same, as though he had said, that the conspiracy of the people had been discovered or proved, as it is said of thieves when found out, that they are caught in the very act. So God says here, that it was no matter of dispute whether the people had designedly and from sheer wickedness perverted his true and lawful worship; the conspiracy, (36) he says, is sufficiently notorious
We then understand the meaning of the Prophet to be, — that not a part of the people was implicated in impiety, but that all, from the least to the greatest, were together defiled, and that this was done, not by some foolish impulse of the moment, but designedly, for they banded together; and further, that this was sufficiently evident, so that they could no longer contend as to the fact, for their wickedness was sufficiently manifest.
And he says between Judah and Israel (37) There is here implied a sharp reproof; for we know that these two kingdoms had not only entertained a hidden grudge, but fiercely contended with one another, Since then the discord had been such between the ten tribes and the tribe of Judah, that it was as it were an insane hatred, so that they wished wholly to destroy one another, for the Jews sent for the Egyptians when the Israelites had called to arms the Syrians and the Assyrians for the destruction of Judah. Since then they so inimically treated one another for so many ages, what did this now mean? What a monstrous thing it was, that they conspired together to subvert the worship of God, to overturn everything true in religion, and to set up their own idols! We now then perceive the meaning of the Prophet; he intimates, that they had in all other things been enemies, and that they only united in this one thing, that is, in carrying on war against God, in subverting his worship, and rendering void his law. We hence see what the Spirit of God had in view in saying, that a conspiracy was found out; which was, that the Prophet might not use many words, as though the matter was doubtful! God then bids him positively to declare this fact, like at scribe who records the sentence of a judge; and thus God shews that he dealt with the Jews, as men deal with those who are condemned.