When God specified what the ark was to be loaded with He provided for the worship needs of Noah and his family. Clean animals were required and so they were available when Noah landed.
This sacrifice is a very significant one. The earth had just been cleansed from idolatry and violence and every sin imaginable. At this point, as Noah makes the sacrifice, every human on the planet stands right with God. I don’t know whether Noah knew that the sacrifice he made was a shadow of things to come, but it was. He was looking forward to Christ in this sacrifice. Looking forward as God did in Genesis 3:15, “I will put enmity between you and the woman and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel.”
This point marks a new beginning in the history of mankind. The line of Messiah is set. He will not come from the line of Cain. He will come from the line of Seth of whom Noah is descended. The Lord is pleased with the sacrifice of Noah.
We need to note the Lord’s promise. The Lord is not going to strike down the inhabitants of the earth again until the earth is destroyed. He has assured the success of His plan and no further measures of this kind will be needed. When I was in elementary school my classmates and I went through drills with regard to what to do in case of nuclear attack. Questions were asked all around the planet as to whether a potential nuclear war would be the end of life for this planet. The answer was right there in God’s book. “While the earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease.” The promise for mankind is in the harvest.
Our text also has something to say about the doctrine of total hereditary depravity (which teaches that we are born in sin and wholly depraved). Verse 21 refutes this idea with this phrase, “for the intention of man’s heart is evil from his youth.” This is a far cry from being born sinful.