Jeremiah 30:3, [The days are coming, declares the Lord, when I will bring my people Israel and Judah back from captivity...]The book of Ezra records the return of Judah from captivity. You do not find any mention of the 10 tribes of Israel in this book.
The book of Nehemiah also records the return of Judah and does not mention any of the ten tribes of Israel that had been carried in to captivity earlier.
Jeremiah 31:35, [This is what the Lord says, he who appoints the sun to shine by day, who decrees the moon and the stars to shine by night, who stirs up the sea so that its waves roar. The Lord Almighty is his name: Only if these decrees vanish from my sight, declares the Lord, will the descendants of Israel ever cease to be a nation before me.]
Jeremiah 33:17, [For this is what the Lord says: David will never fail to have a man to sit on the throne of the house of Israel.] and in verse 20, [This is what the Lord says: If you can break my covenant with the day and my covenant with the night, so that day and night no longer come at their appointed time, then my covenant with David my servant-and my covenant with the Levites who are priests ministering before me-can be broken and David will no longer have a descendant to reign on his throne.]
This prophecy has never been fulfilled by the nation of Judah..... and the sun, the moon and the stars still shine. History tells of the return of Judah, as does the Bible. Israel must still be somewhere, not knowing who they are, but having still a descendant of David on their throne or the word of God is useless!
The dude on the throne of David would be Jesus.