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

A rainbow was the sign God placed in the sky as the covenant with Noah.

In Genesis 9, after Noah leaves the Ark, God establishes a covenant with Noah, his descendants, and every living creature. The rainbow is described as the visible sign of that covenant and as a reminder of the promise that a flood would not again destroy all flesh.

The passage presents the rainbow as appearing in the clouds. It links the natural phenomenon to a theological promise made after the Flood. The covenant is broader than Noah’s immediate family because the text explicitly includes future generations and living creatures.

A common mix-up is to treat the rainbow as a sign given before Noah entered the Ark. In Genesis, it appears after the waters have receded and Noah has left the vessel. The story also includes the earlier olive leaf, but that is a sign of receding water, not the covenant sign.