John Calvin Commentary Genesis 9:24

"And Noah awoke from his wine, and knew what his youngest son had done unto him." — Genesis 9:24 (ASV)

And Noah awoke. It might seem to some that Noah, although he had just cause for anger, still conducted himself with too little modesty and gravity; and that he should, at least, have silently mourned over his sin before God, and also, with shame, have given proof of his repentance to men.

But now, as if he had committed no offense, he fulminates with excessive severity against his son. Moses, however, does not here relate reproaches uttered by Noah under the excitement of rage and anger, but rather introduces him speaking in the spirit of prophecy.

Therefore, we should not doubt that the holy man was truly humbled (as he ought to have been) by a sense of his fault, and honestly reflected on what he deserved; but now, having received the grant of pardon and his condemnation being removed, he proceeds as the herald of Divine judgment.

Indeed, it is not to be doubted that the holy man, endowed with an otherwise gentle disposition and being one of the best of parents, would pronounce this sentence upon his son with the most bitter grief of mind. For he saw him miraculously preserved among a few and having a place among the very flower of the human race.

Now, therefore, when with his own mouth he is compelled to separate him from the Church of God, he doubtless would grievously mourn the curse upon his son.

But by this example, God would admonish us that the constancy of our faith must be retained if at any time we see those fail who are most closely united to us, and that our spirits should not be broken; indeed, that we must exercise the severity which God commands in such a way as not to spare even our own deepest affections.

And since Noah does not pronounce such a harsh sentence except by Divine inspiration, it behooves us to infer from the severity of the punishment how abominable in the sight of God is the impious contempt of parents, since it perverts the sacred order of nature and violates the majesty and authority of God in the person of those whom he has commanded to preside in his place.