What sign did God set in the sky as his covenant with Noah?

God set a rainbow in the sky as the sign of the covenant with Noah. In Genesis 9, the rainbow marks God’s promise never again to destroy all living creatures with a flood of that scale.

The covenant follows Noah’s departure from the ark and his offering on dry land. The text presents the rainbow as a visible reminder of the promise, associated not only with Noah and his descendants but also with every living creature. It therefore functions as a universal sign within the story.

The rainbow is not the signal that told Noah to leave the ark; that decision comes after the waters recede and the ground dries. It is also distinct from the dove’s olive leaf, which indicated that vegetation had reappeared. Those two images belong to different stages of the narrative.