אָ֥ז הָלְמ֖וּ עִקְּבֵי־ס֑וּס מִֽדַּהֲר֖וֹת דַּהֲר֥וֹת אַבִּירָֽיו׃
Then did the horsehoofs stamp By reason of the prancings, the prancings of their mighty ones.
Read kabbalistic (mystical) interpretation of Judges 5:22: and classical mystical sources.