[Such an idiom he knows not, and so he can only take it literally.]

Rather than his foot I should like to see my spear pierce his mouth, or an arrow slung by my bow. Then might his perverse tongue be curbed ere he use it to defile the women of worthy men like myself. That he lives still is only for the distance between us and the unfamiliar landscape of this desert, in which I know not where he cowers.

[Translation: I don't know where this asshole is, so I have no choice but to let him live.]