起信論疏 1.10

1.10

所言「論」者，建立決了、可軌文言，判說甚深法相道理，依決判義，名之為論。總而言之，大乘是論之宗體、起信是論之勝能，體用合舉，以標題目，故言大乘起信論也。

As for what is called a "treatise" (śāstra): establishing decisive, exemplary words and phrases, discerning and expounding the principles and profound marks of phenomena; relying on the meaning of decisive discernment, it is called a treatise. In sum, Mahāyāna is the treatise's essential doctrine, and awakening faith is the treatise's supreme efficacy. Combining essence and function to designate the title, it is therefore called the Treatise on the Awakening of Faith in the Mahāyāna.