Because he hath appointed a day - This is given as a reason why God commands people to repent. They must be judged; and if they are not penitent and pardoned, they must be condemned. See the notes on Romans 2:16.
Judge the world - The whole world - Jews and Gentiles.
In righteousness - According to the principles of strict justice.
Whom he hath ordained - Or whom he has constituted or appointed as judge. See the Acts 10:42 notes; John 5:25 notes.
Hath given assurance - Has afforded evidence of this. That evidence consists:
(1) In the fact that Jesus declared that he would judge the nations John 5:25-26; Matthew 25; and,
(2) God confirmed the truth of his declarations by raising him from the dead, or gave his sanction to what the Lord Jesus had said, for God would nor work a miracle in favor of an impostor.