Sudras are not eligible to study the Vedas, so can a sudra study the Vedas when he becomes a Vaisnava?
From the absolute point of view, when one becomes a pure Vaisnava, he automatically attains the status of a brahmana, whatever caste one may belong to.
The Vedas are divided into two sections:
- Instructions regarding karma, the performance of prescribed duties.
- Instructions regarding tattva, the Absolute Truth.
Those who are qualified as brahmanas in a worldly sense are eligible to study the Vedas that promote karma.
And those who are brahmanas by spiritual qualification are qualified to study the Vedas that promote tattva.
Pure Vaisnavas can study and teach the Vedas that promote spiritual truth, no matter what caste they are born into, and it is practically observed that they do so. It is said in the Brhad-aranyaka Upanisad (4.4.21):
“A brahmana is a sober and spiritually enlightened person who clearly knows para-brahma, and serves Him through prema-bhakti which is a manifestation of the highest knowledge.”
It is also said in the Brhad-aranyaka Upanisad (3.8.10):
“O Gargi, he who quits this world without knowing the supreme imperishable being, Sri Visnu, is a wretched miser, whereas he who quits this world knowing the supreme being is recognized as a brahmana.”
Manu has said the following in regard to those who are brahmanas by vyavaharika, or social considerations. Manu-smrti (2.168)
“A brahmana, ksatriya, or vaisya becomes twice-born by investiture with the sacred thread, and this prepares him for studying the Vedas. If a dvija fails to study the Vedas after receiving the sacred thread, and instead studies other subjects such as economics, science or logic, he and his family members quickly become degraded in this very life to the status of sudras.”
Svetasvatara Upanisad (6.23) explains the eligibility to study the Vedas that promote spiritual truth:
“All the confidential truths described in this Upanisad will be revealed to that great soul who has the same exclusive, uninterrupted, transcendental devotion (para-bhakti) for his guru that he has for Sri Bhagavan. “
The word para-bhakti in the above verse means suddha-bhakti (pure bhakti). I don’t want to elaborate any further on this topic. You should try to understand it yourself. In short, those who have faith in ananya-bhakti are eligible to study the Vedas that promote tattva, spiritual truth, and those who have already attained ananyabhakti are eligible to teach those Vedas.