In the biblical Noah’s Ark story, a rainbow signified God’s covenant after the Flood.
Genesis 9 presents the rainbow as the sign of a covenant between God and Noah, his descendants, and every living creature. The covenant follows the departure from the ark and the restoration of life on the land.
The passage says that whenever the rainbow appeared in the clouds, God would remember the everlasting covenant not to destroy all living creatures again by a flood. In this context, the rainbow functions as a visible reminder of the promise.
The rainbow had symbolic importance before and beyond the Genesis narrative in later Jewish, Christian, and wider cultural traditions. The story’s specific claim is theological and literary; it is not an account of the physical origin of rainbows, which are explained scientifically by refraction, reflection, and dispersion of sunlight in water droplets.