[Their wisdom] cannot be understood by any Śrāvaka or Pratyekabuddha because the [present] Buddhas attended on many hundreds of thousands of billions of [past] Buddhas, and practiced the innumerable teachings of those Buddhas bravely and strenuously to their far-flung fame until they attained the profound Dharma which you have never heard before, [and became Buddhas,] and also because [since they became Buddhas] they have been expounding the Dharma according to the capacities of all living beings in such various ways that the true purpose of their [various] teachings is difficult to understand.

But then the three vehicles are all provisional exigencies (ch’üan). And the Greater Vehicle does not contradict that by which it becomes great. Therefore, [the Buddha] does not mention it, [the Greater Vehicle]. The two vehicles are in diametrical opposition to the sphere of “great.” This refers to [what they] “cannot know.”

[…they attained the profound Dharma which you have never heard before…]
If the reason why this is so is not explained, how can one believe it? [The Buddha] had to make repeated explanations. Accumulating [what he was supposed] to do in such a way, [“in former times the Buddha”] attained to the ultimate [achievement]; that is what is meant by “that had never been before.” [The phrase stating that the Buddha’s wisdom is] incalculable conjoins with the [next] phrase with the word wisdom. This thus explains effect by means of cause.

[…they have been expounding the Dharma according to the capacities of all living beings…]
Words and traces represent external compliance [with li or reality]. By following the traces one might overlook the meaning. Being ignorant of the meaning, one encounters difficulty in understanding [what is real]. This [phrase] joins with the phrase the gateways of their wisdom. Now that the reason has been explained, the subtle meaning will reveal its face (literally, “turn its head”).