Jer 3:6

“(Verse 6 and following) And the Lord said to me in the days of King Josiah: Have you seen what the adulteress Israel has done? She went upon every high hill and under every leafy tree and committed adultery there. And I said, after she had done all these things: Return to me, but she did not return. And her treacherous sister Judah saw that I had dismissed the adulteress Israel and had given her a bill of divorce. But her treacherous sister Judah did not fear, but she also went and committed adultery. She defiled the land with her adulterous acts and committed adultery with stone and wood. And in all this, her treacherous sister Judah did not return to me with her whole heart, but in falsehood, says the Lord. The torments of some are the remedies of others. And when a murderer is punished, he receives indeed what he has done, but others are deterred from the crime. Therefore, when the ten tribes, which were called Israel, were captured by the Assyrians and taken to Media, the two tribes of Judah and Benjamin, which should have feared similar things and turned their whole minds towards God, overcame the crimes of the ten tribes. And they followed idols to such an extent that they placed a statue of Baal in the Temple of God, which is called an idol by Ezekiel, set up for zeal and emulation of the Lord. But it speaks under the figure of two sisters, because from one are generated Abraham, Isaac, and Jacob, by the stock, and the former is called the adversary, the latter the rebellious one. For the former completely turned away from God, immediately worshipping golden calves in Dan and Bethel. But the latter, in whose possession was the Temple and the true religion of God, gradually departed from the Lord (3 Kings 12). And for this reason, she is called the rebellious one. According to the spiritual interpretation, prophecy about heretics is this: those who, thinking themselves wise in heretical cunning, ascend the mind of pride with knowledge of a false name; and, defiled by the pleasures of this flesh, expose their fornication under every leafy and pleasant tree. When they are delivered to the devil for the destruction of the flesh, it often happens that the house of Judah, that is, the confession and true faith, is not at all frightened by their example but commits much greater evils. And they contaminate the land of the Church with the ease of their fornication, committing adultery with stone and wood, following the teachings that are against God. But if an ecclesiastical man wishes to correct someone who has gone astray, and to cut away the rotten flesh, and to bring back to repentance those who have followed falsehood: and nonetheless they continue to adhere to the ancient error under the guise of Ecclesiastical truth, it can be said of them: In all these things, her treacherous sister Judah has not turned back to me with her whole heart, but in deceit. But this prophecy was fulfilled during the time of Josiah, a righteous king, under whom Jeremiah began to prophesy.”

“It is written in the law: "You shall not commit adultery." This is rightly observed according to the simple meaning of the letter by one who is still in bondage to foul passions. But by one who has already forsaken these dirty acts and impure affections, it must be observed in the spirit, so that he may forsake not only the worship of idols but also all heathen superstitions and the observance of auguries and omens and all signs and days and times, or at any rate he should not be entangled in the conjectures of words and names that destroy the simplicity of our faith. This is the kind of fornication by which Jerusalem is said to have been corrupted, the fornication "on every high hill and beneath every leafing tree." The Lord criticized Jerusalem for this through the words of the prophet, "Let them stand and save you, these astrologers who studied the stars and counted the months so as to tell from these what was coming to you."”

“Those who place themselves far from your care and choose to serve idols will reap the destructive fruit of defection. He calls idolatry infidelity here. God likewise says also through Jeremiah, "She went up every high hill and under every green tree and was unfaithful there. I said, after all this infidelity of hers, 'Return unto me,' and she did not return." Again, "She committed adultery with tree and stone," meaning, "Leaving me, her spouse, she served false gods." Accordingly, here too he called the worship of idols infidelity.”