A voice was heard. — Yes, the guilty wife was there, but she was also penitent. The “high places” which had been the scene of the guilt of the sons of Israel, where the cries of their orgiastic worship had been heard, now echoed with their weeping and supplication (or, more literally, the weeping of suppliant prayers), as they called to mind the hateful sins of the past.
Related Commentaries of Jeremiah 3:21
Jeremiah 3:21
21 A voice was heard upon the high places, weeping and supplications of the children of Israel: for they have perverted their way, and they have forgotten the LORD their God.