And Noah built an altar to the LORD and took from every clean animal and of every clean bird and offered a burnt offering on the altar. And the LORD smelled a soothing aroma. And the LORD said unto His heart, “I will not again add to curse the earth for the sake of man, because the formation of the heart of man is evil from his youth, and I will not again add to smite all living things which I have done”, Genesis 8:20–21.
Noah’s offering was a soothing, sweet-smelling aroma to God because it was offered in response to God saving Noah and his family. Able offered this same type of offering in contrast to Cain, who offered the works of his hands in Genesis 4:3–4.
In response to Noah’s offering, God gave a promise to never again flood the earth in this manner, nor destroy all living things for the sake of man. The formation of the heart of man is evil from his youth because of the nature and condemnation that Adam passed down (Genesis 5:3; Romans 5:12).