John Chrysostom

And hence he was not afraid to say, that God was "able to raise him up, even from the dead." "From whence also he received him in a figure," that is in idea, by the ram, he means. How? The ram having been slain, he was saved: so that by means of the ram he received him again, having slain it in his stead. But these things were types: for here it is the Son of God who is slain. And observe, I beseech you, how great is His lovingkindness. …

Homily on Hebrews 25 ↗

Theophylact of Ohrid

It is worthy of admiration that he, having no other son in whom he could expect the fulfillment of the promise, but having only one, nevertheless offered him as a sacrifice. Why then? Because of his great faith. For he believed that God was "able," even after his slaying, to raise him from the dead and fulfill the promise, and through him, brought back to life, to multiply his seed. But in what sense was Isaac the only-begotten, when he also had Ishmael? …

Commentary on Hebrews ↗

Oecumenius

"considering that God was able even to raise him from the dead." Do you see how by faith Abraham did everything? For he believed that God could even raise him from the dead after he was sacrificed. "from which, figuratively speaking." And Abraham himself and Isaac himself. For it is fitting concerning the two. But see this, "figuratively." Abraham was a type of God the Father, and Isaac, of the Son of God. …

The Pseudo-Oecumenian Catena on Hebrews ↗

Thomas Aquinas

606. – Then (v. 19b) he shows what he merited by faith; because, since nothing remained but to immolate him, an angel called him, and, in place of his son, he immolated a ram sticking fast by the horns. But this was a parable, i.e., a figure of Christ to come. For the ram sticking fast by the horns among the briars is the humanity which suffered, fixed to the cross. And so it is clear that the figure was not at all equal to the one prefigured. …

Commentary on Hebrews ↗