John Calvin Commentary Leviticus 18:26

"Ye therefore shall keep my statutes and mine ordinances, and shall not do any of these abominations; neither the home-born, nor the stranger that sojourneth among you;" — Leviticus 18:26 (ASV)

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 to influence them more strongly, He at the same time presents the way pointed out to them in the Law, which would not allow them to go astray, if only they did not refuse to follow God.

For it was not surprising that the Gentiles, who were destitute of light, were drawn aside in every direction. But while they thus proved their blindness, it was fitting for true believers, on the contrary, to testify that they were not children of darkness, but of light. Paul seems to allude to this when he exhorts believers not to walk as the Gentiles do, in the vanity of their mind (Ephesians 4:17).

For this reason, God not only commends to them His precepts and statutes, but also His ordinances (custodias), because He had omitted nothing in the Law that would be useful for the direction of men’s lives. The sum is that unless they constantly order themselves by the doctrine that enlightens them, the same destruction that was about to overwhelm the Canaanite nations also awaited them.