In Genesis, God established a rainbow as the visible sign of the covenant after Noah’s flood.
Genesis 9:12–17 presents the rainbow as the sign of a covenant between God, Noah, his descendants, and every living creature. The covenant promises that a flood will not again destroy all flesh, and the rainbow is described as appearing in the clouds as a reminder.
The passage gives the sign a universal scope: it is not limited to Noah’s family or to humans. Animals and the earth are included in the covenant language. This is one reason the rainbow became a major symbol in religious art and later popular culture.
The rainbow is sometimes confused with the dove and olive leaf, which appear earlier as signs that the waters were receding. In Genesis, those birds and plants belong to the flood narrative, while the rainbow is specifically the post-flood covenant sign.