首楞嚴義疏注經 8.84

8.84

躡前信心也。妙信常住，不偏不邪，純一真如，故云真信明了。一切圓通者，了三科法無不是如也。無明妄想既亡，陰界自然解脫，故云不能為礙。

This builds upon the preceding mind of faith. Wondrous faith permanently abides, neither biased nor deviant, and is purely one tathatā; hence it says 'true faith is clearly understood.' 'Everything is perfectly penetrated' means understanding that none of the dharmas of the three categories are not suchness. Since avidyā and delusional thoughts are gone, the aggregates and dhātus are naturally liberated; hence it says 'cannot obstruct [it].'