Philo Judaeus De Opificio Mundi 103

And besides what has been already said, the growth of men from infancy to old age, when measured by the number seven, displays in a most evident manner its perfecting power; for in the first period of seven years, the putting forth of the teeth takes place. And at the end of the second period of the same length, he arrives at the age of puberty: at the end of the third period, the growth of the beard takes place. The fourth period sees him arrive at the fullness of his manly strength. The fifth seven years is the season for marriage. In the sixth period he arrives at the maturity of his understanding. The seventh period is that of the most rapid improvement and growth of both his intellectual and reasoning powers. The eighth is the sum of the perfection of both. In the ninth, his passions assume a mildness and gentleness, from being to a great degree tamed. In the tenth, the desirable end of life comes upon him, while his limbs and organic senses are still unimpaired: for excessive old age is apt to weaken and enfeeble them all.