XVIII. (63) On which principle also it is that he also calls Israel, who was the younger brother in point of time, “the first born Son,”{19}{#ex 4:22.} judging of him by his merit, signifying thereby that, since to see God is the most clear proof of primogeniture, he is in consequence pardoned as the eldest offspring of the uncreate incomprehensible God, conceived by that virtue which is hated among men, and to whom the law enjoins that “the honours due to seniority shall be paid, as being the Eldest.”{20}{#de 21:17.} (64) On this account also the number seven is produced in its order, subsequently to the number six, but in power it is superior to every other number, and differs not from the unit, and Moses also shows us this in the conclusion of his account of the creation, where he says, “And God ceased on the seventh day from all the works that he had made; and God blessed the seventh day, and hallowed it,” because on it he ceased from all his works which God had begun to make, {21}{#ge 2:2.} (65) and after that he concludes his account in these words, “This is the book of the generation of heaven and of earth when they were made, on the day in which God made the heaven and the earth; and these things were done in the first day, so that the seventh day is referred to the unit which is the first day and the beginning of the whole. I have dwelt at length on this topic, with the object of showing more plainly the opinion which Cain thought it right to build up like a city.