Genesis 29:27-30

27. Fulfil her week. Laban now is become callous in wickedness, for he extorts other seven years from his nephew to allow him to marry his other daughter. If he had had ten more daughters, he would have been ready thus to dispose of them all: yea, of his own accord, he obtrudes his daughter as an object of merchandise, thinking nothing of the disgrace of this illicit sale, if only he may make it a source of gain. In this truly he grievously sins, that he not only involves his nephew in polygamy, but pollutes both him and his own daughters by incestuous nuptials. If by any means a wife is not loved by her husband, it is better to repudiate her than that she should be retained as a captive, and consumed with grief by the introduction of a second wife. Therefore the Lord, by Malachi, pronounces divorce to be more tolerable than polygamy. (Malachi 2:14.) Laban, blinded by avarice, so sets his daughters together, that they spend their whole lives in mutual hostility. He also perverts all the laws of nature by casting two sisters into one marriage-bed, so that the one is the competitor of the other. Since Moses sets these crimes before the Israelites in the very commencement of their history, it is not for them to be inflated by the sense of their nobility, so that they should boast of their descent from holy fathers. For, however excellent Jacob might be, he had no other offspring than that which sprung from an impure source; since, contrary to nature, two sisters are mixed together in one bed; in the mode of beasts; and two concubines are afterwards added to the mass. We have seen indeed, above, that this license was too common among oriental nations; but it was not allowable for men, at their own pleasure, to subvert, by a depraved custom, the law of marriage divinely sanctioned from the beginning. Therefore, Laban is, in every way, inexcusable. And although necessity may, in some degree, excuse the fault of Jacob, it cannot altogether absolve him from blame. For he might have dismissed Leah, because she had not been his lawful wife: because the mutual consent of the man and the woman, respecting which mistake is impossible, constitutes marriage. But Jacob reluctantly retains her as his wife, from whom he was released and free, and thus doubles his fault by polygamy, and trebles it by an incestuous marriage. Thus we see that the inordinate love of Rachel, which had been once excited in his mind, was inflamed to such a degree, that he possessed neither moderation nor judgment. With respect to the words made use of, interpreters ascribe to them different meanings. Some refer the demonstrative pronoun to the week; others to Leah, as if it had been said, that he should not have Rachel until he had lived with her sister one week. But I rather explain it of Rachel, that he should purchase a marriage with her by another seven years’ service; not that Laban deferred the nuptials to the end of that time, but that Jacob was compelled to engage himself in a new servitude.