וַיְהִ֗י כִּרְאוֹת֙ שָׂרֵ֣י הָרֶ֔כֶב כִּ֥י לֹא־הָיָ֖ה מֶ֣לֶךְ יִשְׂרָאֵ֑ל וַיָּשֻׁ֖בוּ מֵאַחֲרָֽיו׃
And it came to pass, when the captains of the chariots saw that it was not the king of Israel, that they turned back from pursuing him.
Read midrashic interpretation of II Chronicles 18:32: and classical rabbinic exegesis.