Leviticus 18:27

For, &c. These "doings" are specially legislated against, because these were the corruptions pertaining to the origin and character of the Nephilim (App-25). These formed the nations of Canaan, and this was why they had to be destroyed by the sword of Israel, as those in the days of Noah had to be destroyed by the Flood. Leviticus 18:24 are emphasized by the other way of putting the facts.