Isaiah 20:3-4

Then the Lord YAHWEH said, “Just as my servant Isaiah has walked naked and barefoot for three years as a prophetic sign and a wonder as a warning of what is coming to Egypt and Cush, so will the king of Assyria lead away the captives of Egypt and Cush, both young and old. They will be stripped and barefoot, with buttocks bared, to publicly humiliate Egypt.