肇論新疏 2.196

2.196

《華嚴》明佛智廣大，《金光》談如智獨存，豈曰默然如空、無知無照。無心心者，一非妄有故，二寂而能照故。問：無心之心，應不應機邪？答：又非不應等。後得無私，但隨感而現。現無現相，故云爾爾。即前云「功高不仁」等。亦可即寂故不應、即照故應。以今不應之應，顯上無心之心。上體，此用。

The Avataṃsaka clarifies that the Buddha's wisdom is vast and great, and the Suvarṇaprabhāsa discusses that tathatā-wisdom alone abides; how could it be said to be silent like empty space, without knowing and without illumination? The "mind of no-mind" is because, first, it is not deluded existence, and second, because while still, it can illuminate. Question: Does the mind of no-mind respond to capacities or not? Answer: "Nor does it not respond," and so forth. Post-attainment [wisdom] is impartial; it merely manifests in accord with stimuli. Its manifestation is without the marks of manifestation, hence it is said to be thus. This is what was referred to earlier as "its merit being high, it is not benevolent," and so on. One may also say: precisely because it is still, it does not respond; precisely because it illuminates, it responds. Through the present "response of non-response," the aforementioned "mind of no-mind" is revealed. The former is substance; the latter is function.