'Buttocks' in the Bible

Therefore Hanun took David’s servants, shaved them [cutting off half their beards], and cut off their garments in the middle as far as their buttocks, and sent them away [in humiliation].

in the same way the king of Assyria will lead away the Egyptian captives and the Cushite exiles, young and old, stripped and barefoot, even with buttocks uncovered—to the shame of Egypt.