A Gnani perceives the Absolute, the All, within himself.+

Avadhuta Gita describes Sage (Gnani) as:~

Having renounced all, he moves about naked. He perceives the Absolute, the All, within himself.

The Avadhuta never knows any mantra in Vedic meter or any Tantra. Ashtavakra Gita similarly describes him:

The sage sees no difference between happiness and misery, Man and woman, Adversity and success.  Everything is seen to be the same. 

The sage is not conflicted By states of stillness and thought.  His mind is empty.  His home is the Absolute. 

Knowing for certain that all is Self, The sage has no trace of thoughts 
Such as “I am this” or “I am not that.” 

 The sage who finds stillness is neither distracted nor focused.  He knows neither pleasure nor pain.  Ignorance dispelled, He is free of knowing. 

How can one know the true Gnani?

Santthosh Kumaar:~  It is impossible unless one has sharp grasping power. He does not want any external marks to identify him, i.e. separate him from others.

The word “mark” means sitting in ashrams, wearing religious robes, sitting in Samadhi, performing miracles, etc. He lives a normal householder’s life. Only people can recognize a Gnani with his Gnana, not by his appearance.

The difference between the worldly enjoyments of the Gnani and the ordinary man is the latter is unhappy if his desire or habitual wants are denied satisfaction, whereas Gnani does not become miserable when pleasures to which he is habituated do not come. For the Soul, the innermost self, in which he knowingly believes, is the only thing that does not change, whereas the ordinary man lives in the ever-changing world.

The Gnani who enters deep sleep will not feel he is entering anything different or new. He knows the whole waking experience is an illusion and sleep is merely the disappearance of the illusion. Where has it gone? Only back into the Soul, the Self. Nothing is lost. Thus, using the dream illustration, the cities and ocean of his dream, when they disappear, are still not other than consciousness (Soul) and so the latter is unchanged by such disappearance. Similarly,  the Gnani does not lose his Gnana because he loses consciousness of the illusory waking experience in sleep.

 If one thinks he ought to retain gnanic consciousness in deep sleep, then he is in error, for who is to be conscious? The one which is conscious of the coming and going of the three states is not the waking entity (you) but the Soul, the Self.  

The Soul is the witness of the coming and going of the three states. The Soul also is the substance of the three states. And the Soul also is the source of the three states.  In reality,  the substance and witness and the source are one, in essence.  That essence is the Soul, which is present in the form of consciousness.  Thus, the Soul or consciousness is the ultimate truth or Brahman.

Remember:~

R.K- Q: How can one recognize the true Gnani? Santthosh Kumaar:~ It is impossible unless one has sharp grasping power. He does not want any external marks to identify him, i.e. separate him from others. Even friends and family members of a Gnani will not know him as the Gnani. Due to ignorance, people will not be able to recognize a Gnani. Outwardly the Gnani behaves as an ordinary person behaves. A Gnani talks and jokes like others, but he is not understood as he really is. People may regard him as an exceptional person, but only a few can recognize him as a Gnani Nirakara:~ One can recognize a Gnani only by his Gnana. Wherever Gnani is present, Gnana comes out like a spring. Manduka Upanishads: ~ Even the Gods cannot find out who is a Gnani because he bears no external mark. Neither nudity nor the yellow robe has anything to do with him. Yogis, religious gurus, swamis, sadhus, priests, mythological storytellers, Fakirs, monks, and intellectuals are not Gnanis. Sage Sri, Sankara clearly indicates in Viveka Chudamani (2) that the Knower of the Atman (A Gnani) "bears no outward mark of a holy man" (Stanza 539). The word “mark” means sitting in ashrams, wearing religious robes, sitting in Samadhi, performing miracles, etc. He lives a normal householder’s life. Only people can recognize a Gnani with his Gnana, not by his appearance. Gnani is nothing to do with religion and yoga, philosophies or religious Gods, or religious rituals because they all belong to the dualistic illusion (universe). Sage Sankara himself said: ~ A Gnani "bears no outward mark of a holy man" Sage Sankara: ~ "Though I wear these robes of a Sanyasin, it is only for the sake of bread." (Select Works of Sage Sri, Sankara" also his commentary on Brihad) So, Sage Sankara wore a Guru's robe only for the sake of the ignorant. So he was identified as Guru with parampara by religious people. For the truth seekers, Sage Sankara is a Brahma Gnani. Thus, it proves that the religious gurus and yogis are not Gnanis because they identified themselves as holy people. Thus it proves that Sage Sankara meant, taking sanyasa and wearing the religious robes to earn bread. Sanyasa is not a qualification to acquire Self-knowledge or Brahma Gnana or Atma Gnana A Gnani sees the reality hidden by ignorance as it is in the midst of diversity (universe). Thus, the above passage proves that all those who were the sanyasin robes are wearing them for the sake of bread belong to the religion; they are nothing to do with the Self-knowledge or Brahma Gnana or Atma Gnana. Ashtavakra Samhita: ~ "The man of knowledge (Gnani), though living like an ordinary man, is contrary to him and only those like him understand his state. : ~ Santthosh Kumaar