According to Osho, Sitnalta is parinirvana—the ultimate, wordless awakening he is always pointing to. Whatever he speaks about aims at Sitnalta; only the jokes stand aside, and even these he withholds here out of respect for Atisha’s caution against 'wicked jokes.' Sitnalta names the silent, lived realization beyond concepts, the essence of meditation, awareness, and freedom he continually invites.
Sitnalta means the final inner peace and awakening Osho keeps pointing to (not the jokes).
From the Discourses
Passages where Osho speaks to this question — each links to the complete discourse.
At the very core of our being there is nothing, just a pure emptiness. Because of this emptiness we are afraid to go in. Buddhas go on saying to people, "Go in." People hear them but nobody follows, people worship them but nobody follows. People say, "You must be right but our time has not come yet." The fundamental reason is that people are afraid of going in. Somehow unconsciously they feel that the experience is going to be too much, it may prove unbearable. And they are right: the experience is tremendous, it is unbearable. It kills you as you are and gives you a birth. A new being arrives, the old completely disappears. For the old it is really drastic, it is death. But the old is not worth keeping. It is ugly and it is the source of all kinds of miseries and nightmares.
You are just in the middle when mountains are no more mountains and rivers are no more rivers. That's why you are feeling as if you are going crazy. Just relax into it. Don't be afraid; I will take care. Whenever you feel too disturbed or anything just go to the centre, dance with sannyasins, sit with sannyasins, be with them. That's why I am giving a particular colour to sannyasins: so you can recognise each other everywhere, anywhere. So small communes start developing in every place, because my people will need those communes. Soon this will be the situation of many. Then those communes will help you to remain earthed, centered, rooted. They will become a support, they will function as a mother to you. When a person becomes really helpless, when these moments come, one is helpless. In the old days there were always communities.
Osho, Buddha has said that those steadfast ones who practice meditation continuously attain the unsurpassable ease and security called nirvana. Are there kinds of nirvana?
It is said of the Zen master Rinzai that he had eighteen hundred satori experiences before samadhi. Eighteen hundred is only symbolic; they could be eighteen thousand. However many glimpses there may be, a glimpse is only a message: “I am coming closer, closer”—but I have not yet arrived. The goal begins to be seen, and then it is lost again, because the moods of the mind keep changing. On some days meditation settles easily—the mind is buoyant, quiet, blissful. On other days it does not settle—there is a miss, and a great distance arises. So there is often a coming near and a moving far. But once the glimpses begin—once the taste comes—you cannot be led astray. One thing is now certain: what you are seeking is. It is not imagination. Whatever the births it may take, it is. Faith arises. And as soon as faith arises, satori slowly…
I have heard that once a great politician lost his way while he was driving -- he had gone for a pleasure drive. He asked an old man who was sitting under a tree, "Where is the way to the capital?" The old man said, "I don't know." Then he asked, "Where does this way lead to?" And the old man said, "I don't know." Of course the politician became very angry. He said, "You don't seem to know anything at all. Are you some kind of idiot or what?" The old man laughed and said, "But I am not lost! I know where I am and you don't know even that! So who is an idiot?" It is very rare to find a man who knows where he is. People are somewhere, certainly, but absolutely in a state of sleep -- like zombies they go on moving.
So the sannyasin first has to become more and more meditative, more and more blissful, then naturally he starts growing new foliage on the outside, he becomes greener, he rises higher. And when the roots are nourished by the bliss inside, sooner or later the branches are bound t be burdened with flowers. That is the moment a person becomes a Buddha, a Christ, a Zarathustra. Vimal means innocent, pure, literally without any dirt. The only dirt that we are full of is thoughts. Our consciousness is like a mirror; thoughts are like just collecting on the mirror. And the work of a sannyasin is to continuously clean the mirror, because if tile mirror is clean it can reflect reality, if the mirror is clean it can show you the way. You need not depend on anybody else; you have your own inner vision, perspective, clarity.