首楞嚴義疏注經 6.238

6.238

普賢菩薩本用心聞，分別眾生所有知見，得大自在。今揀太高，收機不盡，既法界為體，心聞為用，故洞十方，此由普賢因修大行之所感，故中下之機於斯絕分，故云不能入。以眾生心中發明普賢行者方現其身，非同觀音觸物隨現。

Bodhisattva Samantabhadra originally employed mind-hearing to discern all perceptions of sentient beings, obtaining great mastery. Here it is selected out as too high, not encompassing all capacities: since the dharmadhātu is the substance and mind-hearing is the function, it penetrates the ten directions; this is evoked by Samantabhadra's cultivation of great practice in the causal stage, so intermediate and inferior capacities have no share in this; hence it says 'cannot enter'. Only when Samantabhadra's practice unfolds within the minds of sentient beings does his body appear, unlike Avalokiteśvara, who manifests spontaneously in response to whatever is encountered.