I scattered them with a whirlwind: God scattered the Hebrew people among many nations. This scattering was one of the curses for breaking the Mosaic covenant (the agreement God made with Israel at Mount Sinai, Deuteronomy 28:36–37, 64).
The pleasant land was the land of God's covenant promise (Psalm 106:24; Jeremiah 3:19).
Their land became desolate because of God’s judgment. The land was ruined because the people were unfaithful to the covenant and worshiped other gods (Jeremiah 12:10).