大乘起信論裂網疏 5.8

5.8

First: as stated in the sūtras, the dharmakāya of the Tathāgata is ultimate quiescence, just like empty space. When the ordinary and foolish hear this and do not understand its meaning, they cling to the Tathāgata's nature as being identical to empty space, eternal, permanent, and pervasively existent.