John Calvin Commentary Genesis 8:20

"And Noah builded an altar unto Jehovah, and took of every clean beast, and of every clean bird, and offered burnt-offerings on the altar." — Genesis 8:20 (ASV)

And Noah builded an altar unto the Lord. As Noah had given many proofs of his obedience, so he now presents an example of gratitude. This passage teaches us that sacrifices were instituted from the beginning for this purpose: that people should accustom themselves, through such practices, to celebrate the goodness of God and to give him thanks.

The bare confession of the tongue, indeed, even the silent acknowledgment of the heart, might be sufficient for God; but we know how many stimuli our laziness requires. Therefore, when the holy fathers, in former times, professed their piety toward God through sacrifices, their use was by no means superfluous. Besides, it was right that they should always have symbols before their eyes, by which they would be reminded that they could have no access to God except through a mediator.

Now, however, the manifestation of Christ has taken away these ancient shadows. Therefore, let us use those aids which the Lord has prescribed. Moreover, when I say that sacrifices were used by the holy fathers to celebrate the benefits of God, I speak only of one kind: for this offering of Noah corresponds to the peace-offerings and the first-fruits.

But here it may be asked, by what impulse Noah offered a sacrifice to God, since he had no command to do so? I answer: although Moses does not expressly declare that God commanded him to do it, yet a reliable judgment can be formed from what follows, and even from the whole context, that Noah had rested upon the word of God and that, in reliance on the divine command, he had offered this worship, which he knew, undoubtedly, would be acceptable to God.

We have said before that one animal of every kind was preserved separately, and have stated for what purpose it was done. But it was useless to set apart animals for sacrifice unless God had revealed this design to holy Noah, who was to be the priest to offer up the victims.

Besides, Moses says that sacrifices were chosen from among clean animals. But it is certain that Noah did not invent this distinction for himself, since it does not depend on human choice. From this we conclude that he undertook nothing without divine authority. Also, immediately afterwards, Moses adds that the smell of the sacrifice was acceptable to God.

This general rule, therefore, should be observed: that all religious services not perfumed with the fragrance of faith have an offensive odor before God. Let us therefore know that the altar of Noah was founded on the word of God. And the same word was like salt to his sacrifices, so that they might not be insipid.