A class on Bhagavad Gita 9.2 given by His Divine Grace A.C. Bhaktivedanta Swami Prabhupada on November 23, 1966 in New York, NY.
Bhagavad Gita 9.2
rāja-vidyā rāja-guhyaṁ
pavitram idam uttamam
pratyakṣāvagamaṁ dharmyaṁ
su-sukhaṁ kartum avyayam
This knowledge is the king of education, the most secret of all secrets. It is the purest knowledge, and because it gives direct perception of the self by realization, it is the perfection of religion. It is everlasting, and it is joyfully performed.