John Chrysostom

"And He put all things in subjection under His feet." Not simply so set Him above them as to be honored above them, nor by way of comparison with them, but so that He should sit over them as His slaves. Amazing! Awful indeed are these things; every created power hath been made the slave of man by reason of God the Word dwelling in Him. For it is possible for a man to be above others, without having others in subjection, but only as preferred before them. But here it is not so. …

Homily on Ephesians 3 ↗

Theophylact of Ohrid

Lest from the words "having seated above" you conclude that He received only the first honor, he indicates that He also made Him lord over all. And He did not simply subject, but gave in complete subjection: "under His feet." O wonder! He seated the Church on that very same throne as well; because where the head is (i.e. Christ), there is the body also (i.e. the Church itself). The words "above all" indicate that He gave a head that is mighty, which is above all, above angels, above archangels.

Commentary on Ephesians ↗

Jerome

By his foreknowledge he is celebrating what is to come as though it were done already, as I explained above when he says "he has blessed us." … Either this interpretation, or a better one might be: If we are to take account of what has gone before, we should take this to mean that even those things whose will is not subject to him serve him because of their natural condition. So demons, Gentiles and Jews all serve him. …

Commentary on Ephesians 1:22-23 ↗

Thomas Aquinas

The Apostle has previously dealt with the exaltation of Christ both from the viewpoint of his passing over from death to life (1:20a), and from that of his exaltation to the highest glory (1:20b-21). Now he treats of the immense power of his exaltation. Concerning this he does two things: First, he discusses the power of Christ with respect to the whole of creation. Secondly, then his power in relation to the Church (1:22b-23). …

Commentary on Ephesians ↗