Here the living entity is described as sanatana. And the process by which we can understand our sanatana nature, that is called sanatana-dharma, not that having a big tilaka and considering this rascal lump of matter as "I am brahmana. This body is brahmana, and sanatana-dharma." This is all nonsense. Sanatana-dharma means you first of all you must know what you are.
Lecture on Bhagavad-gita 2.24, Hyderabad, November 28, 1972