What does Jeremiah 16:15 mean?

Instead, they'll say, 'As the Lord lives, who brought the Israelites out of the land of the north and out of all the countries where he had scattered them.' For I will bring them back to their own land, the one I gave their ancestors. Jeremiah 16:15 - Modern Text Bible

(God promises a future restoration. The return from exile will be so significant that it will become the new defining story of God's faithfulness.)