ירמיהו, פרק ג׳, פסוק י׳

The Kingdom of Judah stood as a direct witness to the severe punishment and ultimate collapse of its sister, the Kingdom of Israel. Yet, despite seeing this disaster unfold, the people of Judah failed to absorb the critical lesson and did not genuinely return to God. There is a fundamental difference in how the two kingdoms behaved. While Israel never backed away from its sins, Judah displayed outward signs of repentance. They appeared to return to God time and again, acting much like a faithful wife returning to her husband [מלבי״ם].

However, this spiritual awakening was entirely shallow and false. Their repentance was merely lip service [מצודת דוד, ביאור שטיינזלץ]. On the outside, they played the part of the devoted, but deep in their hearts, they still clung to idol worship [מלבי״ם]. This dynamic played out vividly during the reign of King Josiah, and it appears this prophecy was delivered around the time of his religious reforms [רד״ק]. During that generation, the people put on a convincing show of righteousness while continuing to sin in the shadows. They devised a clever trick to maintain their secret worship: they would paint half the image of an idol on the inner side of one door, and the other half on the opposite door. Whenever the king’s inspectors arrived to root out idolatry, the residents would swing their doors wide open to welcome them. By keeping the doors open against the walls, the images were completely hidden from the inspectors' view [רש״י].

Because of this deep-seated hypocrisy, the rebellious Kingdom of Israel is actually viewed as more righteous than Judah. It is for this reason that the prophet is sent specifically to the exiled people of Israel with a call to repent, carrying a promise that God will not hold a grudge forever and will ultimately forgive their sins [מלבי״ם].