大乘起信論略述 1.42

1.42

論。云何三至不增減故　述曰。次下別別釋三大。即分為三。一切法者則染淨也。謂心真如染淨通依故名平等。由平等故在凡加。染而不增。在聖染。染而不減。故名體大也。

[Treatise:] What are the three? […] because it neither increases nor decreases. [Exposition:] Next below, the three greatnesses are explained individually; this is divided into three. "All dharmas" refers to defilement and purity. It means that the mind in terms of suchness is that upon which defilement and purity equally rely, hence it is called "equal." By virtue of being equal, in ordinary beings when defilement is added, it does not increase; in noble ones when defilement [is eliminated], it does not decrease. Therefore, it is called the greatness of essence.