分別功德論 4.9

4.9

The reason why Uruvilvā-Kāśyapa is declared foremost is that since past lives, the three brothers always had a thousand disciples following them. Now encountering the era of Śākyamuni Buddha, the Buddha used eighteen transformations to deliver the thousand men under Kāśyapa; the Buddha's assembly was thereby established, and the offerings of the four requisites arose from this. By this account, Uruvilvā-Kāśyapa was foremost in being able to protect the noble assembly and provide offerings.