וְיֶ֛תֶר דִּבְרֵ֥י מְנַחֵ֖ם וְכָל־אֲשֶׁ֣ר עָשָׂ֑ה הֲלוֹא־הֵ֣ם כְּתוּבִ֗ים עַל־סֵ֛פֶר דִּבְרֵ֥י הַיָּמִ֖ים לְמַלְכֵ֥י יִשְׂרָאֵֽל׃
Now the rest of the acts of Menahem, and all that he did, are they not written in the book of the chronicles of the kings of Israel?
Read midrashic interpretation of II Kings 15:21: and classical rabbinic exegesis.