大乘起信論義疏 1.16

1.16

就初序中二門分別：一明經論作序不同；二者隨文解釋。言不同者，經之與論序相則異，意則同也。言相異者，經中序者凡有二種：一者證信序；二者發起序。言證信者，阿難稟承佛化欲傳末代，先云「如是我從佛聞」證成可信，名證信序。言發起者，如來將說法故先現諸相，招眾有緣，集眾起說，名發起序。論家為序則不如是，無有二序。何故爾者？論主是其自意造論，不傳佛語，不同阿難直傳佛語，故無如是我聞等言以為證信。又須論主無有現相然後造論，不同如來大聖本說，故無發起。但述其意以為序耳，是故異也。言意同者，經之與論同為欲說正之初故，名為同也。

Regarding the initial preface, it is distinguished through two gates: first, clarifying the difference between sūtras and treatises in making a preface; second, following the text to explain it. Regarding their difference: the characteristics of the preface in a sūtra and in a treatise are different, but their intent is identical. Regarding their difference in characteristics: prefaces in sūtras are generally of two kinds: first, the preface certifying faith; second, the preface that initiates [the teaching]. Regarding certifying faith: Ānanda received the Buddha's transforming teachings and wished to transmit them to later ages, so he first said 'Thus have I heard from the Buddha' to certify that it can be trusted, which is called the preface certifying faith. Regarding that which initiates: because the Tathāgata was about to expound the Dharma, he first manifested various marks to attract the assembled beings with whom he had affinity, gathering the assembly and initiating the teaching, which is called the initiating preface. For a treatise author making a preface, it is not like this; there are not two prefaces. Why is this so? The treatise author composes the treatise out of his own intention, not transmitting the Buddha's words; unlike Ānanda who directly transmitted the Buddha's words, he has no words such as 'Thus have I heard' to certify faith. Furthermore, the treatise author does not manifest marks before composing the treatise; unlike the original preaching of the Tathāgata, the Great Sage, there is no initiation. He merely recounts his intention as a preface, and therefore they are different. Regarding their identical intent: both sūtras and treatises are alike in desiring to state the beginning of the orthodox [teaching], and therefore they are called identical.