Isaiah 49:6

He; the Lord, expressed both in the foregoing and following verses. It is a light thing; this is but a small favour in comparison of what follows. To raise up the tribes of Jacob; that remnant of them which shall survive all their calamities and desolations. I will also give thee for a light to the Gentiles, that thou mayest be my salvation; I will make thy labour effectual for the illumination, and conversion, and salvation of the Gentiles in all the parts of the world; which cannot be said of Isaiah with any truth or colour, and therefore must be understood of Christ, by whom this was literally and fully accomplished. By my salvation he means the great instrument and author of that eternal salvation which I will give to the Gentiles.