In the Noah’s Ark story, God set a rainbow in the clouds as the covenant symbol.
Genesis 9 describes God’s covenant with Noah after the Flood and identifies the bow in the cloud as its sign. The covenant promises that a flood will not again destroy all flesh and the earth in the same way.
The rainbow therefore functions in the story as a visible reminder of a promise, not merely as a weather detail. Genesis uses the language of God seeing the bow and remembering the everlasting covenant between God and every living creature on earth.
The covenant is broader than Noah’s household alone. The text repeatedly includes living creatures and the earth, giving the sign a universal scope within the narrative. Later religious and cultural traditions have added many interpretations, but the biblical passage itself directly identifies the rainbow as the covenant sign.