After the biblical Noah's Ark flood, God set a rainbow in the clouds as the sign of a covenant with Noah, his descendants, and every living creature. Genesis 9 presents the rainbow as a reminder that the earth would not again be destroyed by a flood of that kind.
The covenant comes after Noah leaves the ark and builds an altar. God blesses Noah and his sons, permits them to eat animals while prohibiting blood, and establishes the rainbow as the visible sign of the promise. The text connects the sign not merely with Noah's household but with the wider living world.
The rainbow is therefore a covenant symbol within the Genesis narrative, not an object that Noah discovers during the voyage. Popular art often places a rainbow over the ark, but Genesis introduces the covenant sign after the waters have receded and Noah has returned to dry land.