大乘起信論廣釋卷第三．四．五 5.52

5.52

論。云何為四至真如法故　釋曰。下顯四信。即分為四。此初信有得佛因也。其四文中各有二相。初即標其四所信勝德。後起勝行而為願求。信根本者。所信德也。真如之理是諸法本。諸佛所師。諸佛所歸。眾行之源。故云根本。樂念已下正明信相。知此真如為諸法源。樂念觀察。名信根本。

The treatise says: "What are the four? … dharma of tathatā." The commentary says: Below it explains the four types of faith, which are divided into four. This is the first, faith that there is the cause of attaining Buddhahood. In each of the four passages there are two aspects: first, indicating the supreme virtues that are the objects of faith; second, generating supreme practice to aspire and seek. "Faith in the root": this is the virtue that is the object of faith. The principle of tathatā is the root of all dharmas, that which the Buddhas take as their teacher, that to which the Buddhas return, and the source of all practices; therefore it is called the root. From "delighting in contemplating…" downward, it directly explains the attribute of faith. Knowing that this tathatā is the source of all dharmas, delighting in contemplating and observing it is called having faith in the root.