RobH_en_tn/2sa/22/39.md

I devoured them and smashed them

Here David compares himself to a wild animal. AT: "I completely destroyed them like a wild animal devouring its prey" (See: rc://en/ta/man/translate/figs-metaphor)

under my feet

Here "feet" refers to the power and control of victory over his enemies. (See: rc://en/ta/man/translate/figs-metonymy)