In Genesis's Noah's Ark story, God placed a rainbow in the sky as the sign of his covenant with Noah and every living creature. Genesis 9:13 introduces the rainbow after the flood and connects it with God's promise.
The covenant states that a flood will not again destroy all flesh. The sign is therefore presented as a reminder of the promise, not as an object Noah creates or a meteorological prediction. Genesis repeatedly broadens the covenant beyond Noah's family to include animals and the earth.
This rainbow passage comes after Noah leaves the ark, builds an altar, and receives instructions about life after the flood. It is distinct from the earlier rain and flood descriptions. In later Jewish and Christian interpretation, the rainbow became one of the most recognizable symbols associated with the Noah narrative.