When you include 2 Chronicles 25:1–28 as background, you can think of many reasons as to why Amaziah sought to battle with Israel (revenge for the looting by the Israelite soldiers, 2 Chronicles 25:13; overconfidence because he even silenced a prophet of the Lord, 2 Chronicles 25:16; the execution of the judgment of God spoke through the prophet in 2 Chronicles 25:16 and also do note 2 Chronicles 25:20 especially!). But the chronicler of 2 Kings keeps it simple with the timing, simply saying “then.” Literally, Amaziah invites the king of Israel, Jehoash (the same name as the father of Amaziah) to “look one another in the face.” But considering the fact that in 2 Kings 14:11 the same expression is used for the confrontation of the two armies and considering the context, it is clear that Amaziah sought to battle.
8 Then Amaziah sent messengers to Jehoash the son of Jehoahaz, son of Jehu, king of Israel, saying, “Come, let us look one another in the face.”