Левит 18:10

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.

Here is, I. A general law against all conformity to the corrupt usages of the heathen (Lev 18:1-5). II. Particular laws, 1. Against incest (Lev 18:6-18). 2. Against beastly lusts, and barbarous idolatries (Lev 18:19-23). III. The enforcement of these laws from the ruin of the Canaanites (Lev 18:24-30).