Whom the heaven must receive until the times of restitution of all things, which God has spoken by the mouth of all his holy prophets since the world began.
All Commentaries on Acts 3:21 Go To Acts 3
Theophylact of Ochrid
AD 1107
which God has spoken of by the mouth of his holy prophets, from ages past:
Because all the Scriptures of the Old Testament were a constant prophecy of Christ. For both our father Adam himself, and the other fathers, by their deeds bore testimony to His dispensation. All the prophets spoke of the Incarnation, and therefore it is said, As he spoke by the mouth of his holy prophets.
