Matthew Poole and continuators on Judges 15:8

8 And he smote them hip and thigh with a great slaughter ; and he went down and dwelt in the top of the rock Etam .

Upon their Hips and Thighs, peradventure not designing to Kill them, but to make them uncapable of Military employment; or, of doing hurt to the Israelites. Or, He smote them with his Leg upon their Thigh, i. e. without any other Weapon but his Leg and Foot he kicked them, and made them Lame and useless for War.

Heb. with a great stroke; for so it was, even to them whom it did not Kill.

Partly, because there he could better defend himself from his Enemies; and partly, because he would not involve his Brethren in the same danger with himself, but like a Worthy Magistrate, would secure them even with his own greater hazard.