Beyond the well-known prophecies of Isaiah concerning the Messiah, which lesser-known prophecy in Isaiah speaks of the future inclusion of Gentiles into God's covenant people?

A Isaiah 13, which primarily focuses on the destruction of Babylon. B Isaiah 19:19-25, which speaks of an altar to the Lord in Egypt and reconciliation between Egypt, Assyria, and Israel. C Isaiah 22, which mainly concerns the rebuke of Shebna, the royal official. D Isaiah 36, which narrates the invasion of Sennacherib.