大乘起信論義記 3.269

3.269

In the concluding section there are two parts: first, concluding upon what exists in conceptual apprehension; second, from "if the mind is free from" onward, concluding upon what is non-existent in principle. In [explaining that it] is true and not false, the statement "there is only the One True [Mind]..." explains that the doctrine agrees with the simile: because it is omnipresent like space, empty space is taken as a simile. The phrase "This refers to the Tathāgata..." differentiates the doctrine as distinct from the simile, meaning that it is the Tathāgata's innate cognitive nature of enlightenment, so how could it be the same as empty space, which is an illusory phenomenon?