John Calvin Reformed @genevareformer

And in the same sense is to be taken what follows, Surely, deceit is from the hills, and the multitude of mountains, or, from the multitude of mountains, as the letter מ is to be repeated. Here the Prophet more fully expresses the evidence of their repentance, as though he had said, “We have been deceived by the hills and the multitude of mountains; we...

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The charge God exhibits against Israel for their treacherous departures from him, Jer 3:20. As an adulterous wife elopes from her husband, so have they gone a whoring from God. They were joined to God by a marriage-covenant, but they broke that covenant, they dealt treacherously with God, who had always dealt kindly and faithfully with them.

Commenting on Jeremiah 3:20-25

John Gill Reformed Baptist @doctorgill

Truly in vain is salvation hoped for from the hills, and from the multitude of mountains,.... From any natural defence, by hills and mountains encompassing; or from idols worshipped on hills and mountains. So the Targum, "truly in vain we worship upon the hills, and for no profit are we gathered upon the mountains;'' and to this purpose Jarchi and Kimchi interpret it; or from...