One [reason for marriage] is, the propagation of children, signified in that when Moses saith, Gen. ii. 22, “He created them male and female,” not both male nor both female, but one male and the other female; as if he created them fit to propagate other. And therefore when he had created them so, to shew that propagation of children is one end of marriage, he said unto them, “Increase and multiply,” Gen. i. 28; that is, bring forth children, as other creatures bring forth their kind. ... For more, see Henry Smith on marriage and the propagation of children.