4. my people—the Jews. This reading is better than that of Gesenius: "O peoples … nations," namely, the Gentiles. The Jews are called on to hear and rejoice in the extension of the true religion to the nations; for, at the first preaching of the Gospel, as in the final age to come, it was from Jerusalem that the gospel law was, and is, to go forth (Isa 2:3).
law … judgment—the gospel dispensation and institutions (Isa 42:1, "judgment").
make … to rest—establish firmly; found.
light, &c.—(Isa 42:6).