“King Amaziah assembled the men of Judah. He set them by ancestral houses under commanders of the thousands and of the hundreds for all Judah and Benjamin. He mustered those twenty years old and upward. He found that they were three hundred thousand picked troops fit for war, able to handle spear and shield. He also hired one hundred thousand mighty warriors from Israel for one hundred talents of silver. However, a man of God came to him and said. ‘O king, do not let the army of Israel go with you, for Yahweh is not with Israel, with all these Ephraimites. Rather, go by yourself and act! Be strong in battle! If not, God will fling you down before the enemy. God has power to help or over throw.’ Amaziah said to the man of God. ‘But what shall we do about the hundred talents which I have given to the army of Israel?’ The man of God answered. ‘Yahweh is able to give you much more than this.’ Then Amaziah discharged the army that had come to him from Ephraim, letting them go home again. However, they became very angry with Judah. They returned home in fierce anger.”
There was a one line mention of King Amaziah and his battle with the Edomites in 2 Kings, chapter 14. Here the whole episode is expanded. King Amaziah took a census of his army with the men from Judah and Benjamin by ancestral family and divided them into 100s and 1,000s. He had about 300,000 troops over the age of 20 ready to fight with spears. Then he decided to hire 100,000 warriors from the northern Israelite tribes, especially Ephraim, for 100 talents of silver. However, a man of God reprimanded the king. He told the king that he should rely on Yahweh and not the northern Israelites who have not been pleasing to Yahweh. So then the king sent the troops from Ephraim back home without any money. Thus they were very angry with King Amaziah of Judah.