Just as God rested on the seventh day (the seventh day is the end of creation and encompasses within itself the time coextensive with the creation of this world) after He had created the world, so the world, having completed its course, will rest in God on the eighth and final day, the ogdoad, the eternal day. Everyone who exercises diligence with regard to virtue has in mind the future life. Its beginning is called the "eighth," for it follows this perceptible time when the number seven is dissolved. By necessity, we as human beings must establish a foothold in time and prudently use it if we wish to meet the eighth day of eternity. Thus the week of seven days falls back on itself, thereby forming a circle. Such a measure of time's totality exists until things endowed with motion cease and are supplanted by the eighth day. Eschatologically, the Lord's Resurrection is also seen as the eighth day, for it will bring about our own resurrection on the eighth day.
