וְיֶ֙תֶר֙ דִּבְרֵ֣י יְהוֹשָׁפָ֔ט הָרִאשֹׁנִ֖ים וְהָאַחֲרֹנִ֑ים הִנָּ֣ם כְּתוּבִ֗ים בְּדִבְרֵי֙ יֵה֣וּא בֶן־חֲנָ֔נִי אֲשֶׁ֣ר הֹֽעֲלָ֔ה עַל־סֵ֖פֶר מַלְכֵ֥י יִשְׂרָאֵֽל׃
Now the rest of the acts of Jehoshaphat, first and last, behold, they are written in the words of Jehu the son of Hanani, which is inserted in the book of the kings of Israel.
Read midrashic interpretation of II Chronicles 20:34: and classical rabbinic exegesis.