In the Mahabharata, Santi-parva, in the description of giving charity, Lord Sadasiva explains:
"O girl with the beautiful thighs, a brahmana sees everyone equally. He is beyond the modes of nature. He is pure and always situated in Brahman. That is my opinion.
"However, even a sudra who is pure in heart and deed and who controls his senses is equal to a brahmana and he should be worshipped. That is the opinion of Lord Brahma himself.
"A sudra who finds it natural to engage in auspicious activities is equal to a brahmana. That is my opinion.
"Neither birth, nor ritual, nor scholarship, nor family designate one as a brahmana. The way one becomes a brahmana is by his work.
"A so-called high-class person who is degraded in his activities should not be honoured, but a so-called sudra who knows the truth of religion and acts piously is worthy of worship."
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A famous football player in the United States who recently retired was discussing the particular event that made him decide to quit playing. He had been running with the football toward the goal, with two tacklers chasing him. As his legs started giving out, he thought, “Come on, you old legs—don’t give out on me now!” This is like a race car driver who talks to his car: “Keep on going, Betsy—don’t let me down now!” In other words, you use your body as a type of vehicle; but like all vehicles, it is bound to break down sooner or later.
Siddhaswarupananda - Jagad Guru Speaks
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Sri Manu explains:
"By chanting mantras a brahmana attains perfection. Of this there is no doubt. However, a brahmana who neglects his brahmanical duties is no longer a brahmana. He is merely a friend to brahmanas.
"The four varnas and asramas exist in the three worlds in the past, present, and the future also. This is explained in the Vedas."
In the Bhagavad-gita (2.45) the Supreme Personality of Godhead explains:
"The Vedas mainly deal with the three modes of material nature. Rise above these modes, O Arjuna. be transcendental to all of them."
In Srimad Bhagavatam (7.11.35) wise and saintly Narada tells King Yudhisthira:
"If one shows the symptoms of being a brahmana, ksatriya, vaisya or sudra, as described above, even if he has appeared in a different class, he should be accepted according to those symptom of classification."
Manu also explains:
"A so called brahmana who does not study the scriptures should accept the position of another varna. If he continues pretending to be a brahmana, he and his family will become sudras."
In the Bhagavad-gita (3.26) the Supreme Personality of Godhead explains:
"Let not the wise disrupt the minds of the ignorant who are attached to fruitive action. They should not be encouraged to refrain from work, but to engage in work in a spirit of devotion."
In the Vedanta-sutra (1.3.34) it is said:
"Because he approached impelled by unhappiness from hearing an insult, the word 'sudra' here means 'unhappy'."
This sutra is explained by the passage that begins with these words of Chandogya Upanisad (4.1.1):
"There was a man named Janasrutir Pautrayana...."
The following explanation is seen in a sutra of Vyasa (Vedanta-sutra 1.3.35):
"That he is a ksatriya is understood from the clue related by the caitraratha."
In other sutras (Vedanta-sutra 1.3.36-37) it is said:
"This is also so because the scriptures state both the necessity of undergoing the samskaras (rituals of purification) and the exclusion of the sudras from these rituals."
"This is so because care is taken to determine that a student is not a sudra."
These sutras are explained by the passage that begins with these words of Chandogya Upanisad (4.4.4.):
"I do not know into what caste I was born...."
