Albert Barnes Commentary Jeremiah 23:3

"And I will gather the remnant of my flock out of all the countries whither I have driven them, and will bring them again to their folds; and they shall be fruitful and multiply." — Jeremiah 23:3 (ASV)

While there is no promise of restoration for the kings, there is for the people , because they had been led astray by their rulers.

Have driven them – The evil shepherds drove the people into exile by leading them into sin: and God by inflicting punishment.

Their folds – Or, their pastures.