Wǔbǎi Dà Āluóhàn 五百大阿羅漢 (Skt. pañcaśata-arhat; “five hundred great arhats”) is the legendary collective attribution for the redactors of the Sarvāstivāda Mahāvibhāṣā 大毘婆沙論 (KR6l0010, T1545). According to the tradition recorded in the Mahāvibhāṣā’s own colophon and in Xuánzàng’s prefatory remarks (Dà Táng xīyù jì 大唐西域記 j. 3), King Kaniṣka convened a council of five hundred arhats in Kaśmīra (variously placed in the first or second century CE) under the chairmanship of Vasumitra (世友) to systematize Sarvāstivāda doctrine. The council allegedly produced the Upadeśa-śāstra on the sūtras, the Vinaya-vibhāṣā on the Vinaya, and the Abhidharma-vibhāṣā on the Jñāna-prasthāna (KR6l0009) — the last surviving as the Mahāvibhāṣā in Xuánzàng’s translation. Modern scholarship (Lamotte, Willemen) treats the “Kaniṣka council” account as legend or as a much-amplified memory of a real exegetical effort; the Mahāvibhāṣā itself records multiple, often divergent, scholiast opinions and cannot have been the work of a single redactor.