俱舍論頌疏論本 14.77

14.77

The explanation says: The seven classes of disciples, such as monks, must undertake it for the duration of their lives; only the fasting precepts (upavāsa) are received for a single day and night. Because there are only two limits of time for precepts—first, the limit of a lifetime, and second, the limit of a day and night—the duration is definitively so. According to the Sautrāntika, one may receive the fasting discipline for either a single day and night or for many days and nights. The masters of the Vibhāṣā say: "There has never been a sūtra stating that receiving the fasting precepts for longer than a day and night is valid; therefore our school does not accept this doctrine."