楞伽阿跋多羅寶經註解 2.39

2.39

This says that dharmas produced by the six causes do not have the two kinds of characteristics of arising; they are merely discriminated by the false imagination of ordinary beings, hence it is said that they 'neither arise gradually nor arise simultaneously.' From 'Why is this?' onward questions and concludes the reason for non-arising. If all dharmas were to arise instantaneously, then between the cause that is able to produce and the dharma that is produced there would be no distinction, and in seeking the characteristic of the cause it would be unfindable. If all dharmas were to arise gradually, in seeking their essential characteristic it would also be unfindable; hence the simile says: 'Just as with an unbegotten son, how could there be a father's name?'