阿彌陀經疏 1.39

1.39

千二百五十人俱者，示數也。佛初成道度五人訖，乃化三迦葉，謂優樓頻螺、伽耶、那提也，兄弟共有弟子千人。次化舍利、目連，二人共有弟子二百五十人，悉翻邪向正而獲上果，感佛之恩故常隨侍。又《普曜》云：諸經多列千二百五十人者，重其最初歸佛故經家列之，而未必俱在會也。

“Twelve hundred and fifty persons in all” indicates the number. When the Buddha first attained awakening and had finished liberating the five persons, he then converted the three Kāśyapas—namely, Uruvilvā, Gayā, and Nadī; the brothers together had one thousand disciples. Next, he converted Śāriputra and Maudgalyāyana; the two together had two hundred and fifty disciples. All turned from the heterodox toward the correct and attained the supreme fruit, and feeling gratitude for the Buddha’s kindness, they constantly attended upon him. Furthermore, the Puyao jing states: “The various sūtras mostly list twelve hundred and fifty persons because the sūtra compilers esteemed their being the very first to take refuge in the Buddha and thus listed them, though they were not necessarily all present together in the assembly.”