Albert Barnes Commentary Hebrews 11:12

"wherefore also there sprang of one, and him as good as dead, [so many] as the stars of heaven in multitude, and as the sand, which is by the sea-shore, innumerable." — Hebrews 11:12 (ASV)

Therefore sprang there even of one. From a single individual. What the apostle observes here as noteworthy is, that the whole Jewish people originated from one man, and that, as the reward of his strong faith, he was made the father and founder of a nation.

And him as good as dead. So far as the subject under discussion is concerned. To human appearance, there was no more probability that he would have a son at that period of life than that the dead would have.

So many as the stars in the sky, etc. An innumerable multitude. This was in agreement with the promise in Genesis 15:5; Genesis 22:17. These phrases are often used to denote a vast multitude, as nothing appears more numerous than the stars of heaven or than the sands that lie on the shores of the ocean.

The strength of faith in this case was that there was simple confidence in God for the fulfillment of a promise when all human probabilities were against it. This is, therefore, an illustration of the nature of faith. It does not depend on human reasoning, on analogy, on philosophical probabilities, on the foreseen operation of natural laws; but on the mere assurance of God—no matter what the difficulties may be from a human perspective, or the improbabilities against it.