On Yuan Chwang's Travels in India, 629–645 A.D. v1.c9.s5.41

v1.c9.s5.41

In the third tier of high halls of the Kanishka vihāra was the chamber once occupied by the Venerable P'o-li-ssŭ-fo (Pārśva): it was in ruins, but was marked off. This Pārśva was originally a brahmin teacher, and he remained such until he was eighty years old. Then he became converted to Buddhism and received ordination. The city boys hereupon jeered at him as an old and feeble man, and reproached him with wishing to lead an idle life, unable to fulfill the duties of a monk in practising absorbed meditation and reciting the sacred Scriptures. Stung by these reproaches the old man withdrew into seclusion, and made a vow not to lay his side on his mat until he had mastered the canon, and had attained full spiritual perfection and powers. At the end of three years he had completely succeeded, and people out of respect called him Reverend Side (or Ribs) because he had not laid his side on his mat for so long a time.