Albert Barnes Commentary Jeremiah 17:3

"O my mountain in the field, I will give thy substance and all thy treasures for a spoil, [and] thy high places, because of sin, throughout all thy borders." — Jeremiah 17:3 (ASV)

O my mountain in the field - that is, Jerusalem or Zion, called the Rock of the Plain in Jeremiah 21:13. “The field” is the open unenclosed country, here contrasted with the privileged height of Zion.

Or sin - that is, because of your sin.