John Calvin Commentary Hebrews 6:13

"For when God made promise to Abraham, since he could swear by none greater, he sware by himself," — Hebrews 6:13 (ASV)

For when God made a promise to Abraham, etc. His object was to prove that the grace of God is offered to us in vain unless we receive the promise by faith and constantly cherish it in our hearts.

And he proves it by this argument: when God promised a countless offspring to Abraham, it seemed a thing incredible. Sarah had been barren throughout her life; both had reached a sterile old age, when they were nearer the grave than to a conjugal bed. There was no vigor to beget children, as Sarah’s womb, which had been barren through the prime of life, had now become dead.

Who could believe that a nation would proceed from them, equaling the stars in number and like the sand of the sea? It was, indeed, contrary to all reason. Yet Abraham expected this and feared no disappointment, because he relied on the Word of God.

We must, then, notice the circumstance of time, so that the Apostle’s reasoning may appear evident. What he adds refers to this: Abraham partook of this blessing, but only after he had waited for what no one could have thought would ever come to pass.

In this way, glory ought to be given to God. We must quietly hope for what He does not yet show to our senses, but hides from us and for a long time defers, so that our patience may be exercised.

Why God did swear by himself we will soon see. We have explained in the third chapter what the manner of swearing, Except blessing I will bless thee, means: God’s name is not expressed here but must be understood, for unless He performs what He promises, He testifies that He is not to be counted true and faithful.