What does Genesis 9:12 mean?

God restates that this covenant promise to never again use a flood to destroy the earth or wipe out every living thing is between Himself and all of humanity for all generations to come. Interestingly, God also includes all animals as part of this agreement, meaning this vow is not only for the benefit of mankind, but for all living things.

In addition, God will give a visual sign as confirmation of this legally binding contract. This was a common aspect of covenant agreements. Later, when establishing a covenant with Abraham, God will use the sign of circumcision (Genesis 17:11). That sign is revealed in the next verse: God's bow, "set" in the sky, rather than being held in God's hand. The bow was a symbol of warfare, so the symbolism of it being set in the clouds as a human might hang their bow on a wall represents God's peaceful intentions through the covenant.