Leviticus 18:10

None of you shall approach to any that is near of kin to him--Very great laxity prevailed amongst the Egyptians in their sentiments and practice about the conjugal relation, as they not only openly sanctioned marriages between brothers and sisters, but even between parents and children. Such incestuous alliances Moses wisely prohibited, and his laws form the basis upon which the marriage regulations of this and other Christian nations are chiefly founded. This verse contains a general summary of all the particular prohibitions; and the forbidden intercourse is pointed out by the phrase, "to approach to." In the specified prohibitions that follow, all of which are included in this general summary, the prohibited familiarity is indicated by the phrases, to "uncover the nakedness" [Lev 18:12-17], to "take" [Lev 18:17-18], and to "lie with" [Lev 18:22-23]. The phrase in this sixth verse, therefore, has the same identical meaning with each of the other three, and the marriages in reference to which it is used are those of consanguinity or too close affinity, amounting to incestuous connections.

These laws relate to the seventh commandment, and, no doubt, are obligatory on us under the gospel, for they are consonant to the very light and law of nature: one of the articles, that of a man's having his father's wife, the apostle speaks of as a sin not so much as named among the Gentiles, Co1 5:1. Though some of the incests here forbidden were practised by some particular persons among the heathen, yet they were disallowed and detested, unless among those nations who had become barbarous, and were quite given up to vile affections. Observe,
I. That which is forbidden as to the relations here specified is approaching to them to uncover their nakedness, Lev 18:6.
1. It is chiefly intended to forbid the marrying of any of these relations. Marriage is a divine institution; this and the sabbath, the eldest of all, of equal standing with man upon the earth: it is intended for the comfort of human life, and the decent and honourable propagation of the human race, such as became the dignity of man's nature above that of the beasts. It is honourable in all, and these laws are for the support of the honour of it. It was requisite that a divine ordinance should be subject to divine rules and restraints, especially because it concerns a thing wherein the corrupt nature of man is as apt as in any thing to be wilful and impetuous in its desires, and impatient of check. Yet these prohibitions, besides their being enacted by an incontestable authority, are in themselves highly reasonable and equitable. (1.) By marriage two were to become one flesh, therefore those that before were in a sense one flesh by nature could not, without the greatest absurdity, become one flesh by institution; for the institution was designed to unite those who before were not united. (2.) Marriage puts an equality between husband and wife. "Is she not thy companion taken out of thy side?" Therefore, if those who before were superior and inferior should intermarry (which is the case in most of the instances here laid down), the order of nature would be taken away by a positive institution, which must by no means be allowed. The inequality between master and servant, noble and ignoble, is founded in consent and custom, and there is no harm done if that be taken away by the equality of marriage; but the inequality between parents and children, uncles and nieces, aunts and nephews, either by blood or marriage, is founded in nature, and is therefore perpetual, and cannot without confusion be taken away by the equality of marriage, the institution of which, though ancient, is subsequent to the order of nature. (3.) No relations that are equals are forbidden, except brothers and sisters, by the whole blood or half blood, or by marriage; and in this there is not the same natural absurdity as in the former, for Adam's sons must of necessity have married their own sisters; but it was requisite that it should be made by a positive law unlawful and detestable, for the preventing of sinful familiarities between those that in the days of their youth are supposed to live in a house together, and yet cannot intermarry without defeating one of the intentions of marriage, which is the enlargement of friendship and interest. If every man married his own sister (as they would be apt to do from generation to generation if it were lawful), each family would be a world to itself, and it would be forgotten that we are members one of another. It is certain that this has always been looked upon by the more sober heathen as a most infamous and abominable thing; and those who had not this law yet were herein a law to themselves. The making use of the ordinance of marriage for the patronizing of incestuous mixtures is so far from justifying them, or extenuating their guilt, that it adds the guilt of profaning an ordinance of God, and prostituting that to the vilest of purposes which was instituted for the noblest ends. But,
2. Uncleanness, committed with any of these relations out of marriage, is likewise, without doubt, forbidden here, and no less intended than the former: as also all lascivious carriage, wanton dalliance, and every thing that has the appearance of this evil. Relations must love one another, and are to have free and familiar converse with each other, but it must be with all purity; and the less it is suspected of evil by others the more care ought the persons themselves to take that Satan do not get advantage against them, for he is a very subtle enemy, and seeks all occasions against us.
II. The relations forbidden are most of them plainly described; and it is generally laid down as a rule that what relations of a man's own he is bound up from marrying the same relations of his wife he is likewise forbidden to marry, for they two are one. That law which forbids marrying a brother's wife (Lev 18:16) had an exception peculiar to the Jewish state, that, if a man died without issue, his brother or next of kin should marry the widow, and raise up seed to the deceased (Deu 25:5), for reasons which held good only in that commonwealth; and therefore now that those reasons have ceased the exception ceases, and the law is in force, that a man must in no case marry his brother's widow. That article (Lev 18:18) which forbids a man to take a wife to her sister supposes a connivance at polygamy, as some other laws then did (Exo 21:10; Deu 21:15), but forbids a man's marrying two sisters, as Jacob did, because between those who had before been equal there would be apt to arise greater jealousies and animosities than between wives that were not so nearly related. If the sister of the wife be taken for the concubine, or secondary wife, nothing can be more vexing in her life, or as long as she lives.

Leviticus 18:5

5. Ye shall therefore keep my statutes and my judgments; which if a man do, he shall live in them: I am the Lord.

5. Custodite statuta mea, et judicia mea, quae homo si faciat, rivet in ipsis.

5. Ye shall therefore keep my statutes. Although Moses introduces this passage, where he exhorts the Israelites to cultivate chastity in respect to marriage, and not to fall into the incestuous pollutions of the Gentiles, yet, as it is a remarkable one, and contains general instruction, from whence Paul derives his definition of the righteousness of the Law, (Romans 10:5,) it seems to me to come in very appropriately here, inasmuch as it sanctions and confirms the Law by the promise of reward. The hope of eternal life is, therefore, given to all who keep the Law; for those who expound the passage as referring to this earthly and transitory life are mistaken. [195] The cause of this error was, because they feared that thus the righteousness of faith might be subverted, and salvation grounded on the merit of works. But Scripture does not therefore deny that men are justified by works, because the Law itself is imperfect, or does not give instructions for perfect righteousness; but because the promise is made of none effect by our corruption and sin. Paul, therefore, as I have just said, when he teaches that righteousness is to be sought for in the grace of Christ by faith, (Romans 10:4,) proves his statement by this argument, that none is justified who has not fulfilled what the Law commands. Elsewhere also he reasons by contrast, where he contends that the Law does not accord with faith as regards the cause of justification, because the Law requires works for the attainment of salvation, whilst faith directs us to Christ, that we may be delivered from the curse of the Law. Foolishly, then, do some reject as an absurdity the statement, that if a man fulfills the Law he attains to righteousness; for the defect does not arise from the doctrine of the Law, but from the infirmity of men, as is plain from another testimony given by Paul. (Romans 8:3.) We must observe, however, that salvation is not to be expected from the Law unless its precepts be in every respect complied with; for life is not promised to one who shall have done this thing, or that thing, but, by the plural word, full obedience is required of us. The pratings of the Popish theologians about partial righteousness are frivolous and silly, since God embraces at once all the commandments; and who is there that can boast of having thoroughly fulfilled them? If, then, none was ever clear of transgression, or ever will be, although God by no means deceives us, yet the promise becomes ineffectual, because we do not perform our part of the agreement.

Footnotes:

[195] "This some understand only of temporal life and prosperity in this world, Origen, Tostat. Oleaster, Vatablus; and make this to be the meaning, -- that, as the transgressors of the Law were to die, so they which kept it should preserve their life, Thom. Aquin. 1. 2. q. 100, a. 12; but I prefer rather Hesychius' judgment, -- Per quas oeterna vita hominibus datur," etc. -- Willet Hexapla, in loco. There appears to be unusual discrepancy on this point between the commentators, whether Romanist or Protestant. Bush and Holden apply it to temporal life. Bonar says, "If, as most think, we are to take, in this place, the words live in them,' as meaning eternal life to be got by them,' the scope of the passage is, that so excellent are God's laws, and every special minute detail of these laws, that if a man were to keep these always and perfectly, the very keeping would be eternal life to him. And the quotations in Romans 10:5, and Galatians 3:12, would seem to determine this to be the true and only sense here." C.'s view appears to be confirmed by our Lord's reply in Matthew 19:17, referred to in Poole's Synopsis.

Any that is near of kin - כל שאר בשרו col shear besaro, any remnant of his flesh, i.e., to any particularly allied to his own family, the prohibited degrees in which are specified from the 7th to the 17th verse (Lev 18:7-17) inclusive. Notwithstanding the prohibitions here, it must be evident that in the infancy of the world, persons very near of kin must have been joined in matrimonial alliances; and that even brothers must have matched with their own sisters. This must have been the case in the family of Adam. In these first instances necessity required this; when this necessity no longer existed, the thing became inexpedient and improper for two reasons:
1. That the duties owing by nature to relatives might not be confounded with those of a social or political kind; for could a man be a brother and a husband, a son and a husband, at the same time, and fulfill the duties of both? Impossible.
2. That by intermarrying with other families, the bonds of social compact might be strengthened and extended, so that the love of our neighbor, etc., might at once be felt to be not only a maxim of sound policy, but also a very practicable and easy duty; and thus feuds, divisions, and wars be prevented.

The nakedness of thy son's daughter, or of thy daughter's daughter,.... A man might not marry his granddaughter, whether a descendant of his son or of his daughter, nor any further off descending from him in a right line, not his great-granddaughter, and so on; and if he might not marry his granddaughter, much less his own daughter, as Jarchi observes, for the relation is still nearer; therefore that being prohibited, this in course must, though not mentioned:

even their nakedness thou shalt not uncover; neither debauch nor marry such an one:

for theirs is thine own nakedness; which sprung from his, being the descendants either of his son or daughter; the Targum of Jonathan is,"for they are as thy nakedness,''his own flesh and blood.

And consequently of all thy children and children’ s children, and all downwards; for they are a part of thyself, as coming out of thy loins, and out of thy wife, whose nakedness is thine own.

The prohibition of marriage with a granddaughter, whether the daughter of a son or daughter, is explained in the words, "for they are thy nakedness," the meaning of which is, that as they were directly descended from the grandfather, carnal intercourse with them would be equivalent to dishonouring his own flesh and blood.