大乘起信論裂網疏 4.74

4.74

Because it relies on the marks of arising and ceasing of the karmic consciousness and so forth, all those differentiated marks are established. How are they established? Because all phenomena are originally mind-only, truly without discrimination. Because of non-enlightenment, the discriminating mind arises, seeing objects exist, which is called ignorance. (However,) the mind-nature is originally pure; ignorance does not arise. (Therefore,) in tathatā the meaning of 'the radiance of great wisdom' is established. If the mind gives rise to seeing objects, then there is the mark of not seeing; (however,) the mind-nature has no seeing, and thus there is nothing it does not see. (Therefore,) in tathatā the meaning of 'universally illuminating the dharmadhātu' is established. If the mind has motion, then it is not true knowing, not originally pure by nature, not eternal, blissful, self, and pure, not quiescent, but changing and not autonomous. From this, false defilements exceeding the sands of the Ganges completely arise. (However,) because the mind-nature has no motion, (therefore) the meaning of 'true and actual knowing', up to the meaning of 'the marks of pure qualities exceeding the sands of the Ganges', is established. If the mind gives rise to [activity], seeing that there are further objects that can be discriminated and sought, then there is a deficiency in the inner Dharma. (However,) because boundless qualities are the self-nature of the one mind itself, and one does not see that there are further phenomena that can be sought again, it is therefore replete with inconceivable phenomena exceeding the sands of the Ganges that are neither different nor one and without interruption. (Because it inherently possesses such marks of virtue,) tathatā is therefore called the tathāgatagarbha; (because it realizes these inherently possessed marks of virtue,) it is also called the Dharmakāya of the Tathāgata.