Albert Barnes Commentary Jeremiah 3:9

"And it came to pass through the lightness of her whoredom, that the land was polluted, and she committed adultery with stones and with stocks." — Jeremiah 3:9 (ASV)

Lightness - Others render this as in the margin.

Defiled - Rather, profaned. The land especially consecrated to Yahweh’s service was treated by Judah as a common land.