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

God set a rainbow in the clouds as the sign of the covenant with Noah.

In Genesis 9, God establishes a covenant with Noah, his descendants, and every living creature that a Flood will not again destroy all life on earth. The rainbow appears in the clouds as the visible sign associated with that promise. The passage presents it as a reminder of the covenant whenever clouds gather over the earth.

The covenant is broader than a promise made only to Noah’s family. Genesis explicitly includes future generations and living creatures. This makes the rainbow a sign connected with the preservation of the whole living world in the narrative.

The biblical rainbow is sometimes confused with the dove and olive leaf, which belong to the earlier episode of discovering that the waters had receded. In Genesis, the rainbow appears after Noah leaves the ark and after the altar scene.