According to Genesis, a rainbow marked God’s covenant after Noah’s Ark.
In Genesis 9:12–17, God establishes a covenant with Noah, his descendants, and every living creature that survived the Flood. The rainbow in the clouds is presented as the sign of that covenant. The text says that when the rainbow appears, God will remember the everlasting agreement not to destroy all life again with a flood.
The covenant is broader than a promise made only to Noah’s family. It includes animals and future generations, giving the passage a universal scope within the biblical narrative. Genesis also presents the rainbow as something visible in the clouds, linking a familiar natural phenomenon to the story’s religious meaning.
The rainbow is sometimes confused with the dove and olive leaf, which are earlier signs that the waters were receding. Those symbols concern the end of the Flood; the rainbow is the later covenant sign after Noah leaves the ark and builds an altar.