Here "lips" and "tongue" represent the foreigners who speak a different language than the Israelites do. It is implied that this refers to the Assyrian army that will attack Israel. AT: "Yahweh will speak to this people through enemy soldiers who will speak a foreign language" (See: [[rc://en/ta/man/translate/figs-synecdoche]] and [[rc://en/ta/man/translate/figs-activepassive]])