According to Osho, the very question is mistaken. Asking who knows nonbeing presupposes a knower left over; if someone remains, it is not nonbeing. Nonbeing cannot be made an object of knowledge because knowledge requires a subject. Therefore no one knows nonbeing; when knowing and knower disappear, the question itself dissolves.
If someone is there to know nothingness, it isn't nothingness—so the question doesn't make sense.
From the Discourses
Passages where Osho speaks to this question — each links to the complete discourse.
Osho, who is it that knows non-being, and on what basis is it known?
No, this is not a question; this question does not arise. It neither arises nor can it be formed. Because when we say, “Who knows non-being?” we have already assumed that someone remains. Then non-being has not happened. Nirvana is not an expression of bodily experience.
Who knows nonbeing and on what basis can it be known?
The question itself is wrong. This question cannot arise and cannot be formed, because when we ask, "Who knows nonbeing?" we take it that someone remains behind. Then it is not nonbeing.
Do you know who I am?
NO Sir, NOT AT ALL. Because you are not. You are an emptiness -- anatta. No sir. On the surface you may be somebody, but I am not concerned with your surface. In the deepest core you are simply a nobodiness, not even a nobody -- nobodiness. How can I know you? And that's the beauty, because if I can know you I have defined you, I have made you limited by my knowledge. If you can be known, immediately you become an object, you are no more a consciousness. If you can be known you cannot be infinite, and you are -- infinite in your emptiness. How can I know you? Even you yourself cannot know. There exists nothing like self-knowledge. When you come to realize it, it is a NO-SELF-knowledge. When you come to settle with it, suddenly you become aware that the knower and the known have…
There is a very unique thing in the Vedas. “What is all this?”—the seer has asked.
“Perhaps the Divine who made it knows—or who knows, maybe even he does not!” This is something astonishing. God! The Vedic seer says: “What is all this?” “Perhaps—perhaps the One who made it knows; or who knows, maybe even He does not!” They must have been very courageous people. The gist is: even God may not know. In truth, whatever becomes known turns trivial. Once it is known, what remains? To know is to define. Existence has never been defined. Has anyone ever said what it is? That is why Buddha fell silent. Ask him, “Is there God?”—he is silent. “Is there a soul?”—he is silent. That, precisely, was Buddha’s answer! He says: Stop this prattle about soul and God. Who has known? Wake up! Drop the worry about knowing. So there is, first, the race of the doer—that is the race of ego. Then there is the race for…
Osho, you said... then you will find that the devotee is God. The question arises: if one devotee prefers to be God and another wants to remain only a devotee, then which of the two is superior?
The one who wants to be God will not be able to be. And the one who wants to remain a devotee will become God. The question of superior or inferior does not arise, because only one of the two will happen. The one who does not want to be will be. The one who wants to be will be deprived. That very wanting is of the ego. But the matter is a little delicate. Sometimes humility too belongs to the ego. Beware that your humility may not be of the ego. Perhaps you are saying, “No, I don’t want to be,” because you know that those who refuse are the ones who attain. Then you are clever. Then your humility is adulterous. Your humility is not pure, not sacred, not virginal—it is like a prostitute. The one who wants to be God, whose ego says, “I must become God,”…