God's covenant with Noah
After the Flood, God promised never again to destroy the earth by flood and set the rainbow as the sign.
I set my rainbow in the cloud, and it will be a sign of a covenant between me and the earth.
Genesis 9:13 (World English Bible)
Noah's first act on dry ground was to build an altar and worship. God responded with promises: the seasons would continue as long as the earth remains, and a flood would never again destroy all life.
God renewed the command to fill the earth, allowed animals to be eaten for food, and declared human life sacred because people are made in his image (9:6). The rainbow is the covenant's sign.
Dating notes
Same year Noah left the ark.