Isaiah 20:2-4

at that time the LORD spoke by Isaiah the son of Amoz, saying, “Go, and loose the sackcloth from your waist and take off your sandals from your feet,” and he did so, walking naked and barefoot. Then the LORD said, “As my servant Isaiah has walked naked and barefoot for three years as a sign and a portent against Egypt and Cush, so shall the king of Assyria lead away the Egyptian captives and the Cushite exiles, both the young and the old, naked and barefoot, with buttocks uncovered, the nakedness of Egypt.