1 Chronicles 9:1 (BSB)

So all Israel was recorded in the genealogies written in the Book of the Kings of Israel. But Judah was exiled to Babylon because of their unfaithfulness.

From 1 Chronicles 9. Also in the ESV.

Commentary on 1 Chronicles 9:1

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 1 Chronicles 9:1-13: The first verse looks back upon the foregoing genealogies, and tells us they were gathered out of the books of the kings of Israel and Judah, not that which we have in the canon of scripture, but another civil record, which was authentic, as the king's books with us. Mentioning Israel and Judah, the historian takes notice of their being carried away to Babylon for their transgression.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on 1 Chronicles 9:1: So all Israel were reckoned by genealogies,.... Not now by the writer of this book in the preceding chapters; for two of the tribes are not reckoned at all, and the rest but in part; but there had been kept an exact account of them: and, behold, they were written in the book of the kings of Israel; not in the canonical book or books...
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on 1 Chronicles 9:1: So all Israel were reckoned by genealogies; and, behold, they [were] written in the book of the kings of Israel and Judah, [who] were carried away to Babylon for their transgression. (a) Until now he has described their genealogies before they went into captivity, and now he describes their history after their return.
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on 1 Chronicles 9:1: Were reckoned by genealogies - Jarchi considers these as the words of Ezra, the compiler of the book; as if he had said: I have given the genealogies of the Israelites as I have found them in a book which was carried into Babylon, when the people were carried thither for their transgressions; and this book which I found is that which I have transcribed in the preceding chapters.