"God's Covenant With Creation
In Genesis 8:21-22 we get to listen in on God's response to Noah's sacrifice. After blessing Noah and his family, God repeats in 9:11 his pledge from 8:21. He follows up by establishing a physical sign to remind people forever of his everlasting promise.
God responded to Noah's burnt offerings by covenanting with Noah, his descendants, and every living creature in a divine oath to sustain and preserve creation comments stewardship theologian Ronald E. Vallet. God's covenant with Noah had a universal dimension; it was unconditional, unilateral, everlasting and included all people. Because it was made apart from or before Israel, it is upheld independent of the community of faith, Israel. God's covenant with Noah made other covenants possible.
Veteran Bible expositor J. Alec Motyer reflects on the covenant and its sign:
If in the world as constituted before the Flood, there had been such a thing as a rainbow, the Lord here took the familiar and filled it with new meaning, just as later, he would do, with bread and wine. But the word translated "rainbow" is actually "bow", the weapon. It is as if the Lord were saying, "See the war is over I have hung up my bow." As soon as a threat loomed, Noah saw a "sign" that no ultimate threat could again touch him: the Lord had promised.
Only twice in my life have I seen a complete double rainbow, unbroken from horizon to horizon. The two rainbows have taken on a new meaning for me. The primary rainbow is to remind God of the promise of care and concern. The secondary rainbow, subdued and inevitably related to the primary rainbow, speaks to me of our human responsibility as God's stewards. The earth needs human care, and humans have a responsibility toward nonhuman recipients of God's promise of care for the earth and all its inhabitants (see Ge1; 2 and Hos 2:18).
As an addendum to this Genesis account, Motyer notes that in Noah humanity had a new start, a second chance. This is why Genesis 9:1,7 echoes the account of Eden (cf. Ge 1:28). But sadly, Noah, notwithstanding grace, was still a sinner, the founder of a new humanity; and like his father Adam, he was only able to have sons in his own likeness (cf. Ge 5:3). And as Milton writes in Paradise Lost, so it would remain "till one Greater Man Restore us, and regain the blissful Seat" (see Isa 11:1-9; Rev 22:1-5)."