And God said: This is the sign of the covenant which I give between me and you, and to every living soul that is with you, for perpetual generations.  I will set my bow in the clouds, and it shall be the sign of a covenant between me, and between the earth.  And when I shall cover the sky with clouds, my bow shall appear in the clouds:  And I will remember my covenant with you, and with every living soul that beareth flesh: and there shall no more be waters of a flood to destroy all flesh.
 And the bow shall be in the clouds, and I shall see it, and shall remember the everlasting covenant, that was made between God and every living soul of all flesh which is upon the earth. Book of Genesis