金光明經文句記 1.179

1.179

初、約五佛體用釋持。今經宗在釋尊果智，欲彰此智冥四門理，是故特從四佛明之。良以佛智不分彼此，同冥法身不動之性，順性名持。法性是法體、諸佛是報智、壽命是應用，此三皆常，故云無量。

First, explaining "upholding" in terms of the essence and function of the five Buddhas. The central doctrine of the present sūtra resides in the fruit-wisdom of Śākyamuni. Wishing to display that this wisdom merges with the principle of the four gates, it is therefore specifically elucidated through the four Buddhas. Truly, because the Buddha's wisdom does not differentiate between self and other, and equally merges with the immovable nature of the Dharma body, according with this nature is called "upholding." The Dharma-nature is the essence of phenomena, the Buddhas are the reward-wisdom, and the lifespan is the responsive function. Since these three are all eternal, it is called "immeasurable."