Digha Nikaya 1:473
SUJATOYe hi keci, ānanda, etarahi vā mama vā accayena attadīpā viharissanti attasaraṇā anaññasaraṇā, dhammadīpā dhammasaraṇā anaññasaraṇā, tamatagge me te, ānanda, bhikkhū bhavissanti ye keci sikkhākāmā”ti.
Whether now or after I have passed, any who shall live as their own island, their own refuge, with no other refuge; with the teaching as their island and their refuge, with no other refuge—those mendicants of mine who want to train shall be among the best of the best.”