Divrey Hayamim Bais 30:6

6 So the runners went with the iggerot from HaMelech and his sarim throughout kol Yisroel and Yehudah, and according to the commandment of HaMelech, saying, Ye Bnei Yisroel, shuvu (turn, return) unto Hashem Elohei Avraham, Yitzchak, and Yisroel, and He will return to the remnant of you, that are escaped out of the yad of the Kings of Assyria.

Divrey Hayamim Bais 30:6 Meaning and Commentary

2 Chronicles 30:6

So the posts went with the letters from the king and his
princes throughout all Israel and Judah
Both through the kingdoms of the ten tribes of Israel, and the kingdom of the two tribes of Judah and Benjamin:

and according to the commandment of the king, saying;
so they were ordered by the king to say, when they delivered the letters which by the king's commandment they carried; or this was the purport of them, as follows, especially of those that were sent to the ten tribes:

ye children of Israel, turn again unto the Lord God of Abraham, Isaac,
and Israel;
from whom they had revolted, and from whose worship they had departed, by setting up and serving the calves at Dan and Bethel:

and he will return to the remnant of you that are escaped out of the
hand of the king of Assyria;
Pul and Tiglathpileser, who had both invaded their land, and the latter had taken many of their cities, and carried the inhabitants captive, ( 2 Kings 15:19 2 Kings 15:29 ) .

Divrey Hayamim Bais 30:6 In-Context

4 And the thing pleased HaMelech and kol HaKahal.

5 So they established a decree to make proclamation throughout kol Yisroel, from Beer Sheva even to Dan, that they should come to keep Pesach unto Hashem Elohei Yisroel in Yerushalayim, for not many had kept Pesach as prescribed.

6 So the runners went with the iggerot from HaMelech and his sarim throughout kol Yisroel and Yehudah, and according to the commandment of HaMelech, saying, Ye Bnei Yisroel, shuvu (turn, return) unto Hashem Elohei Avraham, Yitzchak, and Yisroel, and He will return to the remnant of you, that are escaped out of the yad of the Kings of Assyria.

7 And be not ye like Avoteichem, and like your achim, which were unfaithful against Hashem Elohei Avoteihem, Who therefore gave them up to a desolation, as ye see.

8 Now be ye not stiffnecked, as Avoteichem were, but yield yourselves unto Hashem, and come to His Mikdash, which He hath set apart as kodesh l’olam; and serve Hashem Eloheichem, that the fierceness of His wrath may turn away from you.