RobH_en_tn/2ki/13/12.md

his might by which he fought against Amaziah king of Judah

Here the strength of Jehoash's army is spoken of as Jehoash's "might." AT: "the power that his army showed when they fought against the army of Amaziah king of Judah" (See: rc://en/ta/man/translate/figs-metonymy)

are they not written in the book of the events of the kings of Israel?

This question is used to remind the reader that the acts of Jehoahaz are recorded in another book. See how this phrase is translated in 2 Kings 1:18. AT: "they are written in the book of the events of the kings of Israel." (See: rc://en/ta/man/translate/figs-rquestion)