>>508294662"'Do not defile yourselves in any of these ways [Sexual Amorality], because this is how the nations that I am going to drive out before you became defiled. Even the land was defiled, so I punished it for its sin, and the land vomited out its inhabitants. But you must keep my decrees and my laws. The native-born and the aliens living among you must not do any of these detestable things, for all these things were done by the people who lived in the land before you, and the land became defiled. And if you defile the land, it will vomit you out as it vomited out the nations that were before you."
-Leviticus 18:24-28.
The aryans did mix the varnas (colors), which gave rise to the caste system to halt it, but it was too little too late.