In the Genesis Ark story, God sets a rainbow in the clouds as the sign of the covenant with Noah.
Genesis 9:12–17 describes the covenant made after the flood. The rainbow serves as a reminder of the promise that a flood would not again destroy all life on Earth. In the passage, the sign is connected to God’s covenant with Noah, his descendants, and every living creature that came out of the Ark.
The biblical account does not present the rainbow as a discovery made by Noah. It presents it as a covenant sign placed in the clouds after the flood. The story also uses the Hebrew term often translated as “bow,” linking the image to a weapon that is symbolically set aside.
Modern meteorology explains rainbows as optical effects produced when light interacts with water droplets. That scientific explanation concerns how rainbows form physically; it does not change the covenant symbolism assigned to the rainbow in Genesis.