John Chrysostom

Didst thou see how what is created and what is begotten are not the same? For otherwise he would not have made the distinction, nor in contrast to the word, "He made" [etc.], have added, "But unto the Son He said, Thy throne, O God, is for ever and ever." Nor would he have called the name, "Son, a more excellent Name," if it is a sign of the same thing. For what is the excellence? For if that which is created, and that which is begotten be the same, and they [the Angels] were made, what is there [in Him] "more excellent"? Lo! …

Homily on Hebrews 3 ↗

Theophylact of Ohrid

Angels, he says, are created beings and creatures, for of them it is said: "You make." But the Son is not a creature: of Him it is not said: "You make"; but King, Master, God, a Throne is ascribed to Him, which is a sign of Kingship, and an eternal throne. This is against Paul of Samosata, who represents the true God and eternal King as a mere man; and against Arius. Here is another sign of the kingdom.

Commentary on Hebrews ↗

Oecumenius

Since the Son is not a creature, but a true offspring, He is no longer referred to as "who makes," (Heb. 1:13) as is said of the angels, but rather, "Your throne, O God, is forever." The throne, however, is a sign of royalty, but the scepter is of righteousness. "The scepter of righteousness." Behold, there is another symbol of royalty, the royal scepter, and the staff.

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

59. – Having proved by scriptural authority that the angels are spirits, the Apostle now proves this with a reason taken on the part of Christ. Hence, he intends here to prove Christ's royal dignity. He does two things: first, he commends Christ's royal dignity; secondly, he shows His fitness for it (v. 9b). In regard to the first he does three things: first, he commends Christ's royal dignity; secondly, the equity of His rule (v. 8b); thirdly, the goodness of His rule (v. 9a). 60. …

Commentary on Hebrews ↗