Then they will know that I am the LORD their God, when I regather them to their own land, not leaving any of them behind after their exile among the nations.
The heathen mistook Israel's ruin for proof that God could not keep His covenant; but when He restores His people after their reformation, all the world will see the truth: Israel fell not by God's weakness but by their own sin, which forfeited His favour and threw them into His enemies' hands. This turns their reproach into His glory.
AI summary
Commenting on Ezekiel 39:23-29
Then shall they know that I am the Lord their God,.... See Gill on Eze 39:22; which caused them to be led into captivity among the Heathen; for their sins and transgressions: and so the Targum adds, "because they sinned before me:'' but I have gathered them into their own land; being now penitent for their sins, and believing in the Messiah: and so the...
The Jews, having no dominion, settled country, or fixed property to detain them, may return at any time without difficulty (compare Hos 3:4-5).