Can a Sudra become a Brahmin in ’this’ birth?
Yes, it is possible through the power of Panchakshari Mantra. As already discussed in question Mantras can have wonderful powers. Similarly through the power of Panchakshara Mantra even a Shudra can become a Brahmana in this very birth.
Panchakshara Mantra is "Namaha Shivaya" or "Om Namaha Shivaya" or "Shivaya Namaha."
In the chapter Glory of Pranava Panchakshara Mantra [Chapter 17 Videsvara Samhita Shiva Purana] various powers of Panchakshara Mantra are told. There Sage Suta also tells that Panchakshara Mantra even can convert Sudra into a Brahmana. As stated in chapter:
क्षत्रियः पञ्चलक्षण क्षत्रत्वमपनेष्यति ।
पुनश्च पञ्चलक्षण क्षत्रियो ब्राह्मणो भवेत् ।।
मन्त्रसिद्धिर्जपाद्यैव क्रमान्मुक्तो भवेन्नर ।
वैश्यस्तु पञ्चलक्षण वैश्यत्वमपनेष्यति ।।
पुनश्च पञ्चलक्षण मन्त्रक्षत्रिय उच्यते ।
पुनश्च पञ्चलक्षण क्षत्रत्वमपनेष्यति ।।
पुनश्च पञ्चलक्षण मन्त्रब्राह्मण उच्यते ।
शूद्रश्चैव नमोऽन्तेन पञ्चविंशतिलक्षत ।।
मन्त्रविप्रत्वमापद्य पश्चाच्छुद्रो भवेद्द्विज।
नारीवाथ नरो वाथ ब्राह्मणो वान्य एव वा ।।
A Kshatriya should recite this mantra five lacs of times, then he is freed from duties of a Kshatriya. By again reciting the mantra by five lakhs (five hundred thousand) of times more, he becomes a Brahmana. By again reciting the same number of the mantra, one achieves the siddhi in the mantra and one gets free from reciting the japam. By performing the japam of the mantra five lacs of times, a Vaisya is freed from Vaisyatwa or remaining as Vaisya. By reciting the mantra for five lacs of times, it is called as mantra Kshatriya. By reciting further by five lacs of times his Ksatriyahood is removed. By further reciting the mantra by five lacks times more, he is called the mantra Brahmana. In case a Sudra adding Namah at the end of the mantra, recites the mantra by twenty five lacs of times, then he achieves the position of a mantra Brahmana. After reciting the japam by twenty five lacs of times again, a Sudra is turned into a pure Brahmana. Irrespective of the one, being a woman, man. a Brahmana or anyone else, all are purified with the reciting of this mantra.
Thus it is clear from the above passage that it is possible for a Sudra to remove his Sudrahood and become a Brahmana through the power of Panchakshara mantra.
From the above passage:
For a Kshatriya:
● If a Kshatriya wants to remove his Kshatroto so that he wants to be free from duties of Kshatriya then he should do japam of Panchakshari Mantra (Om Namaha Shivaya) 5 Lakhs times.
● If he now wants to become Brahmana he should do japam of same Panchakshari Mantra 5 Lakh times. Then he gets the position of Brahmanhood.
For a Vaishya:
● If a Vaishya wants to remove his Vaishatwo (being free from duties of Vaishya) he should do japam of Panchakshari Mantra "Om Namaha Shivaya" for 5 Lakh times. Then his Vaishyahood is removed.
● By doing Japam of Panchakshari further 5 Lakh times he gets to the position of Mantra Kshtraiya.
● By further chanting 5 Lakh more times he can remove his Kshatriyahood.
● By further doing japam 5 Lakh times he reaches to the position of Mantra Brahmana.
● After attaining position of Mantra Brahmana if he does japam for further 25 Lakh times he gets the position of pure Brahmana.
For a Sudra:
● For a Shudra the rule is a little bit different as the passage states " शूद्रश्चैव नमोऽन्तेन" ie. "Shudras should chant with Namaha at the end." ie. Instead of chanting "Om Namaha Shivaya" , one should chant "Shivaya Namaha" (ie. Having Namaha at the end).
● On doing japam of "Shivaya Namaha" mantra 25 Lakh times, a Shudra gets the position of Mantra Brahmana.
● Now after getting position of Mantra Brahmana if he does japam of "Om Namaha Shivaya" 25 Lakhs time he gets the position of Pure Brahamana.
Thus it is possible for a Shudra to become a Brahmana through the power of Panchakshari Mantra. For the information about general method of japam of Panchakshari mantra, one can refer to the beginning of the same chapter of Shiva Purana ie. Vidyesvara Samhita chapter 17 "Glory of Pranava Panchakshara Mantra."
As a Side Note I want to give some features of Panchakshari Mantra here:
▪ It is called Panchakshari Mantra because of five (Pancha) syllables in it "Na" "Ma" "Shi" "Va" "Ya".
▪ Vedas during the time of dissolution enter inside Panchkashari Mantra and thus remain protected as I discuss here.
▪ To the newly formed five headed Brahma Lord Shiva provides Panchakshari through his five heads and thus this mantra is revealed to Brahma at that time. [Linga Purana Part 2 chapter 85].
▪ Panchakshari Mantra is also revealed in Veda Samhita of Yajurveda in the SataRudriya section. Like 16th chapter of Shukla YajurVeda, 4.5.8 of Krishna Yajurveda, 17th Chapter of Kathaka Samhita, 2.9.2 of Maitrayani Samhita and so on..
[Note that for those verses it doesn't matter whether one believes in birth based caste system or Guna based Varna system.]
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