Jeremiah 3:12 - Matthew Poole's English Annotations on the Holy Bible

Go: it may possibly be used here as an adverb of exciting, namely, to go, as is usual; or it notes speed, Go quickly, out of hand; not locally, but set thy face, Jeremiah 2:2, or feet, that way, or by thy office address thyself to them, viz. by way of proclamation, crying aloud; possibly implying the distance of place: this voice may in time reach them, though a great way off. Or rather the deafness of Israel, or the obdurateness of Judah, that they might hear what God saith to Israel, conceive hope, and be reclaimed by their example, and be excited to emulation. Toward the north, i.e. to Assyria and Media, and the regions thereabouts, that lay northward from Judea, whither the ten tribes were carried by Tiglath-pileser and Shulmaneser, 2 Kings 15:29, 2 Kings 17:6. And I will not cause mine anger; upon condition of returning to their former true worship of God, that thereby Judah might be awakened, he promiseth that he will not let his anger, or his face, as in the Hebrew, (because anger principally appears in the face,) his angry face, or countenance, to be upon them; so it is used Leviticus 17:10 Psalms 34:16; and not be inexorable, viz. for ever, which is to be supplied from the next words; for otherwise his anger lay heavy upon them at this time. To fall a metaphor from things on high that drop down to the hurt of whatever is under them, and so Jeremiah 23:34: compare Genesis 19:24. For I am merciful: here is the ground of this conditional promise, taken from the nature of God, that sinners may not despair, Psalms 86:15, Psalms 103:8,9, &c.