大乘起信論義疏 1.15

1.15

自下第二正出所造。此中有三：一者序分；二者從立義分以去，立正宗分；三者從勸修利益分以去，傳持末代。分論必有由，故先明序；由序既興，所說宜題，故次第二明正宗分；聖者造論為利群品，造論既周，嘆勝勸學令不斷絕，故次第三明傳持分也。

Next, the second part directly sets forth the composition itself. Herein there are three: first, the introductory section; second, from the section on establishing the doctrine onward, establishing the main section; third, from the section on encouraging practice and its benefits onward, transmitting and maintaining it for future ages. A treatise must have a reason for being composed, and therefore the preface is first clarified; once the reason and preface have arisen, what is to be expounded should be brought forward, and therefore the main section is clarified second; when a noble one composes a treatise it is to benefit the various kinds [of beings], and once the composition of the treatise is complete, he praises its excellence and encourages learning so that it will not be discontinued, and therefore the section on transmission and maintenance is clarified third.