Daniel 7:27

greatness of the kingdom under . . . whole heaven--The power, which those several kingdoms had possessed, shall all be conferred on Messiah's kingdom. "Under . . . heaven" shows it is a kingdom on earth, not in heaven. people of . . . saints of . . . Most High--"the people of the saints," or "holy ones" (Dan 8:24, Margin): the Jews, the people to whom the saints stand in a peculiar relation. The saints are gathered out of Jews and Gentiles, but the stock of the Church is Jewish (Rom 9:24; Rom 11:24); God's faithfulness to this election Church is thus virtually faithfulness to Israel, and a pledge of their future national blessing. Christ confirms this fact, while withholding the date (Act 1:6-7). everlasting kingdom--If everlasting, how can the kingdom here refer to the millennial one? Answer: Daniel saw the whole time of future blessedness as one period. The clearer light of the New Testament distinguishes, in the whole period, the millennium and the time of the new heaven and new earth (compare Rev 20:4 with Rev 21:1 and Rev 22:5). Christ's kingdom is "everlasting." Not even the last judgment shall end it, but only give it a more glorious appearance, the new Jerusalem coming down from God out of heaven, with the throne of God and the Lamb in it (compare Rev 5:9-10; Rev 11:15).

— Jamieson-Fausset-Brown Commentary (public domain)