“set you as a covenant.” A major part of Jesus’ ministry on earth was to be the covenant sacrifice for Israel—a sacrifice that would also suffice for the sins of the world—and here we see that Jesus was a “covenant” (a covenant sacrifice and covenant maker) with “the people,” i.e., Israel, but also a “light” or blessing, for the Gentiles, the “nations,” i.e., the other nations besides Israel. [For more information on Jesus being a covenant for Israel and a light to the nations, see commentary on Isa. 49:8).
“a light for the nations.” The salvation and everlasting life given by the Messiah was not just for the Jews, even though many of them thought that it was. The first prophecy of the Messiah is the one God made to Adam and Eve in the Garden of Eden in Genesis 3:15, and that was thousands of years before the Jews existed. About 2,000 years after that first prophecy of the Messiah, God promised Abraham that all the people of earth, not just the Jews, would be blessed through him (Gen. 12:3). Then God repeated that promise to Isaac (Gen. 26:4); and to Jacob (Gen. 28:14). Besides those promises, the Old Testament had a number of verses that spoke of Gentiles being included in the Messianic Kingdom, which meant they were granted everlasting life (Ps. 102:15; Isa. 2:2-4; 19:23-25; 42:6; 49:6; 51:4-5; 56:3-7; 60:3; 66:18-21; Ezek. 39:21, 27; Micah 4:2; Hag. 2:7; Zech. 8:22).