The Mahabharata of Krishna-Dwaipayana Vyasa…
“ In consequence of contentment (or Renunciation) they have all attained to Infinity as the Vedas declare. If such men have to come back to the world through the wombs of living creatures, they are never stained by sins which have the unexhausted residue of previous acts for their originating cause. Indeed, one who has led the life of a Brahmacharin and waited dutifully upon his preceptor, who has arrived at settled conclusions (in respect of the soul) , and who has devoted himself to Yoga thus, is truly a Brahmana. Who else would deserve to be called a Brahmana? ”
