Defile not yourselves in any of these things. An old proverb says, that good laws have sprung from evil habits; and God reminds us that for this reason He has been induced expressly to advert to these disgusting and wicked things; for the monstrosities which He mentions would have been concealed in eternal silence had not necessity compelled Him to bring them to light. But since the Canaanitish nations had advanced to such a pitch of licentiousness, that the prodigious sins, which else would have been better concealed, had been but too familiarly known from their wicked habits, God warns His people to beware of their fatal examples. First, when He says that these abominations prevailed amongst the Gentiles, He indicates that evil habits by no means avail as an excuse; nay, that public consent is in vain alleged in defense of vice. But the better to deter them from imitating them, He sets before their eyes the vengeance He is about to take. It is true, indeed, that the nations of Canaan were destroyed for other reasons, but it is not without cause that He sets forth this amongst the rest, for undoubtedly God was offended by such pollutions.
26. Ye shall therefore keep my statutes He here contrasts His Law with the abominations of the Gentiles. The exhibition of His severity, which He had referred to, might indeed have sufficed for the instruction of His people; but in order to influence them more strongly, He at the same time adduces the way pointed out to them in the Law, which would not suffer them to go astray, if only they refused not to follow God. For that the Gentiles, who were destitute of light, should have been drawn aside in every direction was not surprising; but whilst they thus proved their blindness, it behooved true believers, on the contrary, to testify that they were not children of darkness, but of light. And to this Paul seems to allude, when he exhorts believers not to walk, like the Gentiles, |in the vanity of their mind.| (Ephesians 4:17.) On this account God not only commends to them His precepts and statutes, but also His ordinances (custodias,) because He had omitted nothing in the Law which would be useful for the direction of men's lives. The sum is, that unless they order themselves constantly by the doctrine which enlightens them, the same destruction awaited them also which was about to overwhelm the (Canaanitish) nations.