What does 2 Chronicles 30:6 mean?

Messengers went out with letters from the king and his officials, traveling through all of Israel and Judah, following the king’s orders. The letters said, 'People of Israel, come back to the Lord, the God of Abraham, Isaac, and Israel, so he’ll come back to you, the ones who are left after the kings of Assyria took your relatives away.' 2 Chronicles 30:6 - Modern Text Bible

(The message was a heartfelt call to return to God, promising that if the people turned back, God would welcome them, even after all the hardship they’d faced.)