金剛經纂要刊定記 3.63

3.63

法身等者。謂非生因之所生，但了因之所了。由是色身以食為命，法身以慧為命。保偽謂執妄合塵，遺真謂迷理背覺。此皆倒也。養真謂悟理合覺，棄偽謂達妄背塵也。

Regarding "the dharmakāya, and so on": it is not generated by a generative cause (janaka-hetu), but only clarified by a revelatory cause (jñāpaka-hetu). Hence the physical body takes food as its life, whereas the dharmakāya takes wisdom as its life. "Preserving the spurious" means grasping at delusion and conforming to sensory dust; "abandoning the real" means being confused about the principle and turning one's back on awakening. These are both inversions. "Nourishing the real" means awakening to the principle and conforming to awakening; "discarding the spurious" means penetrating delusion and turning one's back on sensory dust.