וְיָֽרָבְעָ֗ם הֵסֵב֙ אֶת־הַמַּאְרָ֔ב לָב֖וֹא מֵֽאַחֲרֵיהֶ֑ם וַיִּֽהְיוּ֙ לִפְנֵ֣י יְהוּדָ֔ה וְהַמַּאְרָ֖ב מֵאַחֲרֵיהֶֽם׃
But Jeroboam caused an ambushment to come about behind them; so they were before Judah, and the ambushment was behind them.
Read midrashic interpretation of II Chronicles 13:13: and classical rabbinic exegesis.