This haftarah opens with one of the prophetic corpus's sharpest statements on the limits of sacrifice: God tells Jeremiah to say that when He brought the ancestors out of Egypt, He did not speak to them about burnt offerings or sacrifices as the primary command at all, but rather commanded them to obey His voice, to walk in the way He had set out, so that it would go well with them.
Jeremiah then recounts a long history of that command being ignored, the people walking in the counsel of their own stubborn hearts rather than obeying, and describes coming devastation so severe that the dead will be so numerous they cannot properly be buried or mourned, their bones eventually scattered and exposed to the sun, moon and stars they had wrongly worshipped instead of God.
The haftarah closes with a separate, celebrated passage instructing that the wise should not glory in wisdom, nor the strong in strength, nor the rich in riches, but that whoever glories should glory in understanding and knowing God, who exercises loving kindness, justice and righteousness on the earth, since these are what God delights in.
The image of bones left unburied and eventually exposed to the very sun, moon and stars the people had wrongly worshipped is one of Jeremiah's starkest single pictures of consequence, tying the specific punishment directly back to the specific object of the misplaced devotion that caused it.