"G.C. Pande, the noted Sanskrit scholar, says that only the Dharmashastra in the post-Vedic period started to pervert the original idea of varna by conflating it with jati. And this period is when the ritual superiority of the brahmins got converted into a more or less formal hereditary right of priesthood."
January 1, 1970
https://en.wikiquote.org/wiki/Caste_system_in_India