觀無量壽佛經義疏 2.21

2.21

"Then Maudgalyāyana, flying like a hawk or falcon, swiftly arrived at the king's place; day after day he conferred the eight precepts upon the king in this manner." When Maudgalyāyana knew of it, he went to attend to the capacity. "Flying like a hawk or falcon" is a metaphor for the speed of his supernormal bases. "Sun" is pronounced *xun*; the dictionary says: "A bird of prey, meaning a fierce bird." The eightfold fast-precepts are limited to one day and one night, so they are received separately day by day; this is the opinion of the Sarvāstivāda school. According to the Chengshi lun, their duration is not restricted. Third, the Buddha sends Pūrṇa to preach the Dharma.