大般涅槃經疏 1.22

1.22

復次五序序四德者，如是總序四德，我聞序樂，一時序淨，住處序常，同聞序我（云云）。例以五序序經要義，皆悉準此不復廣說，餘例思之。

Furthermore, as for the five prefaces prefacing the four virtues: 'Thus' generally prefaces the four virtues; 'I have heard' prefaces bliss; 'at one time' prefaces purity; 'dwelling place' prefaces permanence; and 'hearing together' prefaces the self (and so on). By this example, the five prefaces preface the essential meanings of the sūtra, all conforming to this without further extensive explanation; consider other examples accordingly.