At his feet, i.e. who followed him or his footsteps; possibly he intimates that they were all footmen, the Israelites neither now having, nor otherwise allowed to have, a multitude of horses; and so this is emphatically added, to signify by what contemptible means God overthrew Sisera's great host, wherein there were ten thousand horses, as Josephus reports.
Related Commentaries of Judges 4:10
Judges 4:10
10 And Barak called Zebulun and Naphtali to Kedesh; and he went up with ten thousand men at his feet: and Deborah went up with him.