Charles Ellicott Commentary Genesis 8:21

"And Jehovah smelled the sweet savor; and Jehovah said in his heart, I will not again curse the ground any more for man`s sake, for that the imagination of man`s heart is evil from his youth; neither will I again smite any more everything living, as I have done." — Genesis 8:21 (ASV)

A sweet savour. — Hebrew, a smell of satisfaction. The idea is not so much that the sacrifice gave God pleasure as that it caused Him to regard humanity with satisfaction. The anger at sin which had caused the flood was now over, and there was peace between heaven and earth.

Said in his heart. — Hebrew, to his heart: that is, Jehovah determined with Himself, came to the settled purpose. (Compare Genesis 17:17.)

For the imagination of man’s heart is evil from his youth. — See Genesis 6:5. There seems at first sight to be an inconsistency between the two passages, and the Jehovist is accused of here contradicting the Elohist. For in the former place humanity’s inborn sinfulness is described as an aggravation of its offense, while here it is used as a reason for mercy. But it is a characteristic of the Bible that it states the two sides of every principle with abrupt simplicity, and most heresies have arisen from seizing upon one side only, and omitting the other from view. Humanity is one whose every imagination of the heart is only evil continually. (Compare Matthew 15:19.)

In the antediluvian world, with death indefinitely postponed, these imaginations had been unrestrained, and had therefore led to habitual and inveterate sin; and so justice at last had smitten it. But when humanity strives against them, and sin is the result of infirmity, then mercy heals and grace strengthens the penitent.

When humanity, therefore, began its renewed life by hallowing it with religion, God saw in this the pledge of a struggle on its part after holiness, and the proof that the world would never again become totally corrupt. In this changed state of things, human weakness was a reason only for mercy, and God gave the promise that as long as the world shall last, such a total destruction of humanity and its works upon it shall never again take place by the same agency.