Shoyoroku - Case 48: Vimalakirti's "Not-Two" [1]

Vimalakirti asked Manjusri,
  "What does it mean that the Bodhisattva enters the Dharma-gate of Not-Two?"
Manjusri said,
  "I see it like this: in all phenomena, there are neither words nor
   explanations, neither presentations nor knowledge; it is beyond all
   questions and answers. That is what I understand with 'to enter the
   Dharma-gate of Not-Two'."
Then Manjusri asked Vimalakirti,
  "All of us have finished giving our explanations. Now you should give your
   explanation. What does it mean that the Bodhisattva enters the
   Dharma-gate of Not-Two?"
Vimalakirti remained silent.

[1]: see case 84 of Hekiganroku.
