大乘起信論義記 1.101

1.101

○別釋中有二：初、說聽俱勝，經文尚無紙素之傳，何況須論？二、「如來滅」下，明根緣微劣，須經須論。

In the specific explanation, there are two: first, both teaching and listening are superior, so that the scriptural texts did not even need transmission on paper and silk, much less a śāstra; second, from "After the Tathāgata passed into extinction" onward, it explains that when faculties and conditions are deficient and inferior, both sūtras and śāstras are needed.