On leaving the ark Noah’s first act was to erect an altar, the first of which there is any mention, and offer the sacrifices of adoring thanks and praise to God, who entered into a covenant with him, the first covenant between God and man, granting him possession of the earth by a new and special charter, which remains in force to the present time (Genesis 8:21-9:17). As a sign and witness of this covenant, the rainbow was adopted and set apart by God, as a sure pledge that never again would the earth be destroyed by a flood.