Jehoash did not wait to be attacked. Invading Judaea from the west, and so ascending out of the low coast tract, he met the army of Amaziah at Beth-shemesh (see Joshua 19:21 note), about 15 miles from Jerusalem.
Related Commentaries of 2 Kings 14:11
2 Kings 14:11
11 But Amaziah would not hear. Therefore Jehoash king of Israel went up; and he and Amaziah king of Judah looked one another in the face at Bethshemesh, which belongeth to Judah.