Hebrews 6:15

Having boldly reflected on the faults of the Hebrews, and sufficiently alarmed them, he consoles them, first, by praises, and secondly (which also is the stronger ground), by the thought that they would certainly attain the object of their hope. Moreover he draws his consolation, not from things future, but again from the past, which indeed would the rather persuade them. For as in the case of punishment, he alarms them rather by those things future, so also in the case of the prizes set before them, he encourages them by these things past, showing herein God's way of dealing. And that is, not to bring in what has been promised immediately, but after a long time. And this He does, both to present the greatest proof of His power, and also to lead us to Faith, that they who are living in tribulation without having received the promises, or the rewards, may not faint under their troubles.

And omitting all the rest, though he had many whom he might have mentioned, he brought forward Abraham both on account of the dignity of his person, and because this had occurred in a special way in his case.

And yet at the end of the Epistle he says, that "all these, having seen the promises afar off, and having embraced them, received them not, that they without us should not be made perfect." "For when God made promise to Abraham" (he says) "because He could swear by no greater, He sware by Himself, saying, Surely blessing I will bless thee, and multiplying I will multiply thee. And so after he had patiently endured, he obtained the promise." How then does he say at the end of the Epistle that "he received not the promises," and here, that "after he had patiently endured he obtained the promise"? How did he not receive? How did he obtain? He is not speaking of the same things in this place and in the other, but makes the consolation twofold. God made promises to Abraham, and after a long space of time He gave the things spoken of in this place, but those others not yet.

"And so after he had patiently endured, he obtained the promise." Seest thou that the promise alone did not effect the whole, but the patient waiting as well? Here he alarms them, showing that oftentimes a promise is thwarted through faintheartedness. And this he had indeed shown through the instance of the Jewish people: for since they were faint-hearted, therefore they obtained not the promise. But now he shows the contrary by means of Abraham. Afterwards near the end of the Epistle he proves something more also: that even though they had patiently endured, they did not obtain; and yet not even so are they grieved.

Yet though making a promise and doing it with an oath, he did not immediately fulfill the promise; instead, the patriarch needed great patience, and only with the passage of a great length of time did he thus see the realization of the promise.

"And so, having patiently." You see that the patience of Abraham accomplished something? He said that by being patient he obtained the promise, in order to show the great power of patience, and that it was not the promise alone that accomplished everything; but also patience.
"he attained the promise." And yet in the end, it says that all these, having seen them from afar and embraced them, did not receive the promises, so that they would not be made perfect apart from us. How then does he say here, "he attained the promise?" And we say, he did not speak about the same things. For the things here he has given to him, concerning which he now spoke, but those there, he keeps, concerning which he says at the end of the Epistle, "And the end of all their opposition." (Heb. 12:3) And the end of all opposition and dispute to confirm the things spoken by him is the oath. Both, however, the obtaining and the not yet obtaining, serve as encouragement to the faint-hearted; the one, that we also, if we endure patiently, will obtain; the other, that, since he has not yet obtained it, though perfected many years ago, we who are still struggling are not foolish because we have not yet obtained it.

In what way does he say at the end of the epistle that they "saw them only from afar" and "rejoiced" at the fulfillment of the promises (Heb. 11:13), yet now says that Abraham "received what was promised"? He is not speaking of the same thing here and there; rather, here he speaks of earthly promises, which Abraham received after a long time, while there he speaks of heavenly ones, which he had not yet received. Nevertheless, both—what he received and what he had not yet received—serve as consolation for the fainthearted: the one because we too shall receive if we show patience, the other because if the one who attained perfection so many years before has not yet received, then we are exceedingly foolish to be indignant that we have not yet received. Notice how he said "having patiently endured, he received what was promised," in order to show the great power of patience, and that the promise alone did not accomplish everything, but patience as well. Here he also instills fear in them, making clear by way of the opposite that faintheartedness hinders the fulfillment of the promise. And this is what happened in the wilderness with the ancient people, who grew fainthearted and utterly failed to receive the promise. So then, someone may ask: why did the saints, having endured long, not receive, as it says at the end of the epistle? They will certainly receive. But the murmurers among the people neither received nor will receive.

316. – The effect of the promise was that Abraham, having patiently endured, obtained the promise. For patient endurance consists not only in doing something great, but also in waiting a long time. But Abraham had the promise, although he never possessed the pace of a foot of land, as it says in Ac (7:5); furthermore, even until his old age he possessed no offspring. But he still kept his hope: 'Take, my brethren, for an example of suffering evil, of labor and patience, the prophets who spoke in the name of the Lord' (Jas. 5:10); 'Look unto Abraham your father and to Sarah that bore you' (Is. 51:2).