金光明經文句記 2.166

2.166

二、「法身」下，明就報立三，即身、壽、量也。三中一一言法身者，報智所冥，離法無報，故初身。言非身者，非應佛有分齊身。非不身者，非報佛無分齊身。又非身則非有、非不身則非空，中道法身乃本覺體。始覺冥此，能冥亦忘，為成觀故，彊名報智。二壽、三量，稱本雙非，為物彊指，義皆同身。

Second, from "Dharma body" onward: explaining the establishment of the three based on the reward [body], which are body, lifespan, and measure. In these three, the reason why each mentions the Dharma body is that what reward wisdom merges with is the Dharma—apart from the Dharma there is no reward—and hence it is first the body. Saying "not a body" means it is not the delimited body of a response Buddha. Saying "not non-body" means it is not the non-delimited body of a reward Buddha. Moreover, "not a body" means not existent; "not non-body" means not empty; the Middle Way Dharma body is the substance of original awakening. When initial awakening merges with this, that which can merge is also forgotten; for the sake of fulfilling contemplation, it is forcefully named reward wisdom. The second, lifespan, and the third, measure, match the original double negation; forcefully designated for sentient beings' sake, their meaning is identical to that of the body.