Jeremiah 2:7

A plentiful country. — Literally, a land of Carmel, that word, as meaning a vine-clad hill, having become a type of plenty. So “the forest of his Carmel,” in Isaiah 37:24; elsewhere, as in Isaiah 10:18; Isaiah 32:15, “fruitful.” The LXX. treats the word as a proper name, “I brought you unto Carmel.”

When ye entered. — The words point to the rapid degeneracy of Israel after the settlement in Canaan, as seen in the false worship and foul crimes of Judges 17-21. So in Psalms 78:56. Instead of being the pattern nation, the firstfruits of mankind, they sank to the level, or below the level, of the heathen.