It is a light thing. God rewards his servants according to their works. He is supremely just. He was not content that even Nebuchadnezzar should be insufficiently rewarded for the service that he rendered against Tyre (Ezekiel 29:18), and he therefore gave him Egypt in addition as his recompense (Ezekiel 29:20).
It would have been "a light thing"—"too light a thing" (Kay, Cheyne)—to have rewarded the labours of Jesus with the conversion of the Jews only. God therefore gave him as his recompense the gathering in of the Gentiles also, and made him a means of salvation even to the uttermost ends of the earth.
The preserved of Israel; i.e. the "remnant" that had not perished through previous judgments. I will also give thee for a Light to the Gentiles (comp. Isaiah 11:10; Isaiah 34:1; Isaiah 42:6; Isaiah 55:5, etc.
). Greeks ἕλληνες were brought into contact with our Lord himself shortly before his crucifixion (John 12:20). He wrought a miracle for a Syro-Phoenician woman (Mark 7:25-30). His apostles, after a little time, understood that the gospel was for the world at large, and declared that in Christ there was no difference between Jew and Greek, nay!
between Jew and barbarian. Christ had died for all—had come to be a Light to all, would have all come into his Church and obtain salvation through union with him. That thou mayest be my Salvation. Christ is called "Salvation," as the Bearer of salvation—he through whom alone can any man be saved (Acts 4:12).
So he is called "Peace" (Micah 5:5), as the Giver of peace.