注大乘入楞伽經 6.21

6.21

亦如向古城道，本來自有，不由士夫行之始有，以譬真如法界本來自有，不由如來說之始有。以明不說也。

It is also like the road leading to an ancient city, which is originally existent of itself, and does not begin to exist only when a person walks upon it; this serves as an analogy showing that the dharma-realm of true suchness is originally existent of itself, and does not begin to exist only when the Tathāgata proclaims it. This clarifies the meaning of not speaking.