No more [cease], Śāriputra, will I say because the Dharma attained by the Buddhas is the highest Truth, rare [to hear] and difficult to understand.

Because it already has been declared that the three vehicles are not real, what should logically follow is an explication of the One Vehicle. Even though [the Buddha] has said that they are unreal, this is still short of what is proper, not yet sufficient to startle their minds from attachment to them. If he says it again, they are certain to be bewildered and puzzled. Hence, he shouts, saying, “cease.” How could one argue that their puzzlement can be dispelled without speaking. Although the One has not yet been pinpointed, the idea has been roughly Suggested. Hence, he says, “we need speak no more.”