On Yuan Chwang's Travels in India, 629–645 A.D. v2.c19.81

v2.c19.81

The three men here mentioned were brothers, the eldest, called in this passage Kāśyapa, being generally distinguished as Uruvilva Kāśyapa from the name of the place at which they lived. These brothers were great scholars and magicians, they were worshippers of the element of fire, and they had numerous disciples. Their home was at the town of Uruvilva on the Nairañjana (Phalgu) river, the youngest living a little down the stream. The story of their conversion is told in several of the Buddhist books and our author refers to it a little farther on.