Behold, God is with us at our head, and his priests with their battle trumpets to sound the call to battle against you. O sons of Israel, do not fight against the LORD, the God of your fathers, for you cannot succeed.”
Abijah's mother was called Maachah, the daughter of Absalom, Ch2 11:20; here she is called Michaiah, the daughter of Uriel. It is most probable that she was a grand-daughter of Absalom, by his daughter Tamar (Sa2 14:27), and that her immediate father was this Uriel. But we are here to attend Abijah into the field of battle with Jeroboam king of Israel. I.
Commenting on 2 Chronicles 13:1-12
But Jeroboam caused an ambushment to come about behind them,.... While Abijah was making his oration, he detached a party from his army, which got about, and lay in ambush, behind the army of Abijah: so they were before Judah; Jeroboam and the greater part of his army: and the ambushment was behind them; which Jeroboam had sent thither.
And, behold, God himself [is] with us for [our] captain, and his priests with sounding trumpets to cry alarm against you. O children of Israel, fight ye not against the LORD God of your fathers; for ye shall not prosper. (l) Because their cause was good and approved by the Lord, they did not doubt the success and victory.