金剛經纂要刊定記 5.227

5.227

幽邃。經意云：校量不及，佛不具說者，以此經義及持者果報，皆不可心思言議故也。

"Profound and secluded": the meaning of the sūtra is that the reason it cannot be matched by comparison and the Buddha did not speak fully is that both the meaning of this sūtra and the fruition of the upholder cannot be thought by the mind or discussed with words.