大乘起信論裂網疏 3.120

3.120

心相，即指染相。心體，即指染淨所依非染非淨之本體也。染亦依體，以違體故，但名為相。淨亦有相，所謂真如相大，以順體故，直名為體也。

The marks of the mind refer precisely to the defiled marks. The essence of the mind refers precisely to the primordial essence that is neither defiled nor pure, on which defilement and purity rely. Defilement also relies on the essence; because it goes against the essence, it is merely termed a mark. Purity also has marks—namely, the greatness of attributes of tathatā; because it accords with the essence, it is directly termed the essence.