Jamieson, Fausset and Brown on 2 Chronicles 25:10

10. separated them ... the army ... out of Ephraim ... their anger was greatly kindled against Judah--Amaziah, who knew his position as the Lord's viceroy, complied with the prophet's counsel, and, consenting to forfeit the purchase money of the Israelitish soldiers, discharged them. Exasperated at this treatment, they resolved to indemnify themselves for the loss of their expected booty, and so on their return home they plundered all the towns in their way, committing great havoc both of life and property without any stoppage, as the king of Judah and his army had set out on their expedition (2Ki 14:7).