The prohibitions which we find in chap. xviii. are not given as an exhaustive code of laws upon the subjects traversed, but rather deal with certain gross offences against the law of chastity, which, as we know from other sources, were horribly common at that time among the surrounding nations. To indulgence in these crimes, Israel, as the later history sadly shows, would be especially liable; so contagious are evil example and corrupt associations! Hence the general scope of the chapter is announced in this form (ver. 3): "After the doings of the land of Egypt, wherein ye dwelt, shall ye not do: and after the doings of the land of Canaan, whither I bring you, shall ye not do: neither shall ye walk in their statutes." Instead of this, they were (ver. 4) to do God's judgments, and keep His statutes, to walk in them, bearing in mind whose they were. And as a further motive it is added (ver. 5): "which if a man do, he shall live in them;" that is, as the Chaldee paraphrast, Onkelos, rightly interprets in the Targum, "with the life of eternity." Which far-reaching promise is sealed by the repetition, for the third time, of the words, "I am the Lord." That is enough; for what Jehovah promises, that shall certainly be! The law begins (ver. 6) with a general statement of the principle which underlies all particular prohibitions of incest: "None of you shall approach to any that is near of kin to him, to uncover their nakedness;" and then, for the fourth time, are iterated the words, "I am the Lord." The prohibitions which follow require little special explanation. As just remarked, they are directed in particular to those breaches of the law of chastity which were most common with the Egyptians, from the midst of whom Israel had come; and with the Canaanites, to whose land they were going. This explains, for instance, the fulness of detail in the prohibition of incestuous union with a sister or half-sister (vv. 9, 11),--an iniquity very common in Egypt, having the sanction of royal custom from the days of the Pharaohs down to the time of the Ptolemies. The unnatural alliance of a man with his mother, prohibited in ver. 8, of which Paul declared (1 Cor. v. 1) that in his day it did not exist among the Gentiles, was yet the distinguishing infamy of the Medes and Persians for many centuries. Union with an aunt, by blood or by marriage, prohibited in vv. 12-14,--a connection less gross, and less severely to be punished than the preceding,--seems to have been permitted even among the Israelites themselves while in Egypt, as is plain from the case of Amram and Jochebed (Exod. vi. 20). To the law forbidding connection with a brother's wife (ver. 16), the later Deuteronomic law (Deut. xxv. 5-10), made an exception, permitting that a man might marry the widow of his deceased brother, when the latter had died without children, and "raise up seed unto his brother." In this, however, the law but sanctioned a custom which--as we learn from the case of Onan