What was the sign given to Noah after the flood?

The sign given to Noah after the flood was a rainbow.

In the flood narrative of Genesis, God establishes a covenant with Noah, his descendants, and every living creature. The rainbow is designated as the visible sign of that covenant: whenever it appears in the clouds, it recalls God’s promise not to destroy the earth with another flood of that kind.

The rainbow is therefore more than a weather detail in the story. It functions as a covenant symbol involving the whole living world, not only Noah’s family. Genesis describes Noah leaving the ark, building an altar, and receiving the promise after the waters recede.

The dove and olive leaf are related but different details. Noah sends birds from the ark to learn whether the waters have subsided; a dove eventually returns with a freshly plucked olive leaf. That episode signals emerging dry land, whereas the rainbow is the explicit sign of the post-flood covenant.