Once again the "isles of the sea" would be a very direct call to Nephi, as he and his people would see themselves as inhabitants of those "isles of the sea." The promises of the Lord to covenant Israel are being made explicit to Nephi's people as Nephi cites these passages to them.
In this verse, the Lord renews is position with Israel. There is a covenant, and the Lord has, and continues, to honor that covenant. As noted before, the servant who is "given" in this verse might have multiple applications to particular people, from Isaiah to Christ to Joseph Smith. The Lord provides envoys to be the agents of the redemption of Israel and the fulfillment of the terms of the covenant from the Lord's side of the bargain.