大乘起信論廣釋卷第三．四．五 4.89

4.89

論。此以何義至真如平等　釋曰。此顯自他同體所以。文中徵釋。此以何義者徵責自他無別所以。如實等者。約真如答顯其義意。自他同真無有別體。何得身外見有眾生。

[Treatise:] By what meaning is this so? [Because they truly know that all sentient beings and their own selves are equal in tathatā, without difference.] [Commentary:] This reveals the reason for the identical substance of self and other. In the text there is a question and an explanation. "By what meaning is this so?" questions and inquires into the reason for self and other having no distinction. "Because they truly [know]..." and so forth answers by reference to tathatā to reveal its meaning: self and other share the same truth and have no separate substance; how could one see sentient beings existing outside oneself?