Tertullian

“ For the laying down [1] of the law of once marrying, the very origin of the human race is our authority; witnessing as it emphatically does what God constituted in the beginning for a type to be examined with care by posterity. For when He had moulded man, and had foreseen that a peer was necessary for him, He borrowed from his ribs one, and fashioned for him one woman ”

“ From one marriage do we derive our origin in each case; carnally in Adam, spiritually in Christ. The two births combine in laying down one prescriptive rule of monogamy. In regard of each of the two, is he degenerate who transgresses the limit of monogamy. Plurality of marriage began with an accursed man. Lamech was the first who, by marrying himself to two women, caused three to be (joined) “into one flesh.” [7] ”

“ But when the apostle interprets, “The two shall be (joined) into one flesh” [6] of the Church and Christ, according to the spiritual nuptials of the Church and Christ (for Christ is one, and one is His Church) , we are bound to recognise a duplication and additional enforcement for us of the law of unity of marriage, not only in accordance with the foundation of our race, but in accordance with the sacrament of Christ. ”