Albert Barnes Commentary Jeremiah 6:8

"Be thou instructed, O Jerusalem, lest my soul be alienated from thee; lest I make thee a desolation, a land not inhabited." — Jeremiah 6:8 (ASV)

Be thou instructed - Be you chastised: learn the lesson which chastisement is intended to teach you.

Lest my soul - Lest I Myself - not “depart from thee,” God does not willingly leave His people, but - “be torn from you.”