Albert Barnes Commentary Acts 17:31

"inasmuch as he hath appointed a day in which he will judge the world in righteousness by the man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead." — Acts 17:31 (ASV)

Because he hath appointed a day. This is given as a reason why God commands men to repent. They must be judged; and if they are not penitent and pardoned, they must be condemned. (See Barnes on Romans 2:16.)

Whom he hath ordained. Or whom He has constituted or appointed as judge. (See Barnes on Acts 10:42.)

(See Barnes on John 5:25.)

Hath given assurance. He has afforded evidence of this. That evidence consists of:

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 declaration by raising Him from the dead, or gave His sanction to what the Lord Jesus had said, for God would not work a miracle in favor of an impostor.