Note 13 — Chapter XXII · KAPILAVASTU. ITS DESOLATION. LEGENDS OF BUDDHA’S BIRTH, AND OTHER INCIDENTS IN CONNEXION WITH IT.
James Legge translation
They did this, I suppose, to show their humility, for Upâli was only a Śûdra by birth, and had been a barber; so from the first did Buddhism assert its superiority to the conditions of rank and caste. Upâli was distinguished by his knowledge of the rules of discipline, and praised on that account by Buddha. He was one of the three leaders of the first synod, and the principal compiler of the original Vinaya books.