Maitreya Upanishad of Samaveda, Chapter II

Then Lord Maitreya went to Kailas and having reached it asked Him thus: "O Lord! please initiate me into the mysteries of the highest Tattva." To which Mahādeva replied: "The body is said to be a temple. The Jīva in it is Śiva alone. Having given up all the cast-off offerings of Ajñāna, one should worship Him with So’ham (I am He). The cognition of everything as non-different from oneself is Jñāna (wisdom). Abstracting the mind from sensual objects is Dhyāna (meditation). Purifying the mind of its impurities is Snāna (bathing). The subjugation of the Indriyas (sensual organs) is Śauca (purification). One should drink the nectar of Brahman and beg food for maintaining the body. Having one (thought) alone, he should live in a solitary place without a second. The wise man should observe thus: then be obtains Absolution.

"This body is subject to birth and death. It is of the nature of the secretion of the father and mother. It is impure, being the seat of happiness and misery. (Therefore) bathing is prescribed for touching it. It is bound by the Dhātus (skin, blood, etc.), is liable to severe diseases, is a house of sins, is impermanent and is of changing appearance and size. (Therefore) bathing is prescribed for touching it. Foul matter is naturally oozing out always from the nine holes. It (body) contains bad odour and foul excrement. (Therefore) bathing is prescribed for touching it. It is connected (or tainted) with the child-birth impurity of the mother and is born with it. It is also tainted with death impurity. (Therefore) bathing is prescribed for touching it. (The conception of) "I and mine" is the odour arising from the besmeared dung and urine. The release from it is spoken of as the perfect purification. The (external) purification by means of water and earth is on account of the worldly. The destruction of the threefold affinities (of Śāstras, world and body) generates the purity for cleansing Citta. That is called the (real) purification which is done by means of the earth and water of Jñāna (wisdom) and Vairāgya (indifference to objects).

"The conception of Advaita (non-dualism) should be taken in as the Bhikṣa (alms-food); (but) the conception of Dvaita (dualism) should not be taken in. To a Sannyāsī (ascetic), Bhikṣa is ordained as dictated by the Śāstra and the Guru. After becoming a Sannyāsī, a learned man should himself abandon his native place and live at a distance, like a thief released from prison. When a person gives up Ahaṅkāra (I-am-ness) the son, wealth the brother, delusion the house, and desire the wife, there is no doubt that he is an emancipated person. Delusion, the mother is dead. Wisdom, the son is born. In this manner while tvo kinds of pollution have occurred, how shall we (the ascetics) observe the Sandhyās (conjunction periods)? The Chit (consciousness) of the sun is ever shining in the resplendent Ākāś of the heart. He neither sets nor rises; while so, how shall we perform the Sandhyās? Ekānta (solitude) is that state of one without second as determined by the words of a Guru. Monasteries or forests are not solitudes. Emancipation is only for those who do not doubt. To those who doubt, there is no salvation even after many births. Therefore one should attain faith. (Mere) abandoning of the Karmas or of the Mantras uttered at the initiation of a Sannyāsī (ascetic) will not constitute Sannyāsa. The union of Jīva (-Ātmā) (the lover Self) and Parama (-Ātmā) (the higher Self) at the two Sandhis (morning and evening) is termed Sannyāsa. Whoever has a nausea for all Īṣaṇa (desires) and the rest as for vomited food, and is devoid of all affection for the body, is qualified for Sannyāsa. At the moment when indifference towards all objects arises in the mind, a learned person may take up Sannyāsa. Otherwise, he is a fallen person. Whoever becomes a Sannyāsī on account of wealth, food, clothes and fame, becomes fallen in both (as a Sannyāsī and as householder); (then) he is not worthy of salvation.

"The thought of (contemplation upon) Tattvas is the transcendental one; that of the Śāstras, the middling, and that of Mantras, the lowest. The delusion of pilgrimages is the lowest of the lowest. Like one, who, having seen in water the reflection of fruits in the branches of trees, tastes and enjoys them, the ignorant without self-cognition are in vain overjoyed with (as if they reached) Brahman. That ascetic is an emancipated person who does not abandon the internal alms-taking (viz., the meditation upon the non-dual), generating Vairāgya as well as faith the wife, and wisdom the son. Those men (termed) great through wealth, age, and knovledge, are only servants to those that are great through their wisdom as also to their disciples. Those whose minds are deluded by My Māyā, however learned they may be, do not attain Me, the all-full Ātmā, and roam about like crows, simply for the purpose of filling up their belly, well burnt up (by hunger, etc.). For one that longs after salvation, the worship of images made of stone, metals, gem, or earth, is productive of rebirth and enjoyment. Therefore the ascetic should perform his own heart-worship alone, and relinquish external worship in order that he may not be born again. Then like a vessel full to its brim in an ocean, he is full within and full without. Like a vessel void in the ether, he is void within and void without. Do not become (or differentiate between) the Ātmā that knows or the Ātmā that is known. Do become of the form of that which remains, after having given up all thoughts. Relinquishing with their Vāsanās the seer, the seen and the visual, worship Ātmā alone, the resplendent supreme presence. That is the real supreme State wherein all Saṅkalpas (thoughts) are at rest, which resembles the state of a stone, and which is neither waking nor sleeping."