Jacob has covered a wide range of topics, and he is now tying them all together. He has spoken of the Nephites as a branch broken off, although through the comparison to those in Jerusalem as a branch broken off. Nevertheless, he sees his people as parallel to, and therefore inheritors of, the covenants between Jehovah and the children of Israel.
Jehovah’s covenants have always been conditional, something that Jacob has repeated in this sermon with respect to the promise associated with the land. Jacob now ties his people even more directly to that original covenant by noting that they were driven out and led to an isle of the sea. Isaiah had prophesied the gathering of those on the isles of the sea, therefore Jacob’s people are part of those blessings.