Therefore being a prophet, and knowing that God had sworn with an oath to him, that of his descendants, according to the flesh, he would raise up Christ to sit on his throne;
All Commentaries on Acts 2:30 Go To Acts 2
John Chrysostom
AD 407
he goes on with his encomium upon David,
he was a prophet, for he knew that God had sworn an oath to him:
But this he says, that were it but on account of the honor shown to David, and the descent from him, they may accept what is said concerning Christ's resurrection, as seeing that it would be an injury to the prophecy, and a derogating from their honor, if this were not the fact. And knowing, he says, that God had sworn an oath to him— he does not say simply promised