法華玄義釋籤 9.7

9.7

In general, the method of parables employs either real facts or hypothetical assumptions. Just as the Buddha said: 'If trees could understand my words, I would also cause them to attain stream-entry.' Yet trees have no capacity to understand words; the Buddha merely drew this parable for people who understand words. Furthermore, because Subhūti wished to show the greatness of the power of prajñā, he said that even if there were a dharma surpassing nirvāṇa, the power of wisdom could also dismantle it; hence he said it is like an illusion.