Albert Barnes Commentary Jeremiah 3:5

"Will he retain [his anger] for ever? will he keep it to the end? Behold, thou hast spoken and hast done evil things, and hast had thy way." — Jeremiah 3:5 (ASV)

Rather, “Will he, the young husband,” retain, “keep up His anger forever!” These words should be joined to (Jeremiah 3:4).

Behold ... - Rather, “Behold, you have spoken” thus, but you have “done evil things” persistently. The King James Version translates as if Judah’s words and deeds were both evil. Really her words were fair, but her deeds proved them to be false.

And here ends the prophecy, most interesting as showing what was the general nature of Jeremiah’s exhortations to his countrymen during the 14 years of Josiah’s reign. He sets before them God and Israel united by a covenant of marriage, to the conditions of which Yahweh is ever true, while Israel practices with zest every form of idolatry. Therefore, the divine blessing is withheld.

It is an honest and forthright warning, and the great lesson it teaches us is that with God nothing is effective except a real and heartfelt repentance, followed by a life of holiness and sincere devotion to His service.

(Jeremiah 3:6 - 4:4) – “The Call to Repentance”

The former prophecy ended with the denunciation of God’s perpetual anger because of Israel’s obstinate persistence in sin. Now there is an invitation to repentance and the assurance of forgiveness.

The argument is as follows: Israel had been guilty of apostasy, and therefore God had put her away. Unwarned by this example, her more guilty sister Judah persists in the same sins (Jeremiah 3:6–11).

Israel therefore is invited to return to the marriage-covenant by repentance (Jeremiah 3:12–14), in which case she and Judah, accepted on the same condition, will become joint members of a spiritual theocracy (Jeremiah 3:15–18).

The repentance which God requires must be real (Jeremiah 3:19 - 4:4).