In Genesis, a rainbow marks God’s covenant with Noah after the flood.
After Noah leaves the ark, he builds an altar and offers sacrifices. God then establishes a covenant with Noah, his descendants, and every living creature. The rainbow in the clouds is presented as the sign of that covenant.
The promise is that a flood will not again destroy all life on Earth. Genesis describes the rainbow as something that will be seen when clouds gather, serving as a reminder of the covenant. The text links the sign to the relationship between God and the whole living world, not only to Noah’s family.
Rainbows have therefore become closely associated with hope, peace, and divine promise in Jewish and Christian cultural traditions. The biblical narrative does not claim that the rainbow first appeared after the flood; instead, it assigns the existing natural phenomenon a covenant meaning within the story.