So the land enjoyed its Sabbath rest all the days of the desolation, until seventy years were completed, in fulfillment of the word of the LORD spoken through Jeremiah.
We have here an account of the destruction of the kingdom of Judah and the city of Jerusalem by the Chaldeans. Abraham, God's friend, was called out of that country, from Ur of the Chaldees, when God took him into covenant and communion with himself; and now his degenerate seed were carried into that country again, to signify that they had forfeited all that kindness...
Commenting on 2 Chronicles 36:11-21
until the land had enjoyed her sabbaths--The return of every seventh was to be held as a sabbatic year, a season of rest to all classes, even to the land itself, which was to be fallow. This divine institution, however, was neglected--how soon and how long, appears from the prophecy of Moses (see on Lev 26:34), and of Jeremiah in this passage (see Jer 25:9-12)...
To fulfil the word of the LORD by the mouth of Jeremiah, until the land had enjoyed her sabbaths: [for] as long as she lay desolate she kept sabbath, to fulfil threescore and ten years. (l) Who threatened the vengeance of God and 70 years captivity, which he called the sabbaths or rest of the land, .