Chronicles II 20:34

34 And the rest of the acts of Josaphat, the first and the last, behold, they are written in the history of Jeu of Anani, who wrote the book of the kings of Israel.

Chronicles II 20:34 Meaning and Commentary

2 Chronicles 20:34

Now the rest of the acts of Jehoshaphat, first and last
Those that were done at the beginning, and those that were done at the latter end of his reign:

behold, they are written in the book of Jehu, the son of Hanani, who
is mentioned in the book of the kings of Israel;
see ( 1 Kings 16:1 1 Kings 16:7 ) , the same that reproved Jehoshaphat, ( 2 Chronicles 19:2 ) . He wrote a book of his own times, and which was so much esteemed, according to Kimchi, that it was written with, or put along with, the book of the kings of Israel, for so he interprets the phrase; but the Targum understands it of Jehu being the king's historiographer, who had the care and oversight of the diary, journal, or annals of the kings of Israel.

Chronicles II 20:34 In-Context

32 And he walked in the ways of his father Asa, and turned not aside from doing that which was right in the sight of the Lord.
33 nevertheless the high places yet remained; and as yet the people did not direct their heart to the Lord God of their fathers.
34 And the rest of the acts of Josaphat, the first and the last, behold, they are written in the history of Jeu of Anani, who wrote the book of the kings of Israel.
35 And afterwards Josaphat king of Juda entered into an alliance with Ochozias king of Israel, (now this was an unrighteous man,)
36 by acting and going to him, to build ships to go to Tharsis: and he built ships in Gasion Gaber.

The Brenton translation of the Septuagint is in the public domain.