Niyamas are the second accessory of Yoga. Niyamas are ethical, internal and external observances or duties.
5 Niyamas
Patanjali Maharshi mentions, in Sadhana Pada Verse 32, of five observances under Niyama: the practice of internal and external purity, contentment, self discipline, study of scriptures and self surrender.
Saucha/Purity – purification, cleanliness and clarity of mind, communication and physical body. Purification is of two kinds – internal (mental) and external (physical). Mental purity is more important. Physical purity is also needed. Cleanliness is next to godliness. The purity referred here is physical or external purity. When the body is impure, one purifies it. Again the body becomes impure. Again one purifies it. One wants to keep the body always pure, but it constantly becomes impure. Gradually one develops disgust over the body which is full of impurities. Since the same dust and impurity is in the body of others, one ceases contact with others. Slowly the “body idea” drops when one then turns to thinking of the ever pure Atman. Moha and Mamata for the body vanish.
Santosha/Contentment and acceptance of the world, oneself and circumstances exactly as they are, letting go of cravings for what one doesn’t have or rejection of things considered unsavoury. Practicing Santosha ends one’s suffering.
Tapas/intense self discipline and willpower, even through discomfort, recognizes the need to sometimes do what is difficult or unpleasant on one’s path to enlightenment.
Svadhyaha: the study of the scriptures as a tool for introspection, the study of the self and the practice of witnessing the self. Svadhyaha witnesses one in the moment as well as exploring one’s connection with the Divine.
Ishvara Pranidhana: surrender to and contemplation of the supreme Hari, Siva, Krishna or Rama. This includes dedicating and devoting one’s work to a higher power and dissolving the ego.
10 Niyamas
According to the Sandilya Upanishads and the Varuha Upanishads there are 10 Niyama qualities. These are Tapas, Santosha, Astikya, Dana, Isvara Pujana, Siddhanta Sravana, Hrih, Mati, Japa and Vrata:
Tapas. Through the practice of Krichara and Chandrayana Vratas, in accordance with Sastric injunctions, one purifies themselves. Their body becomes emancipated. The sins are destroyed. The Indriyas are controlled. The passion nature of the mind becomes subdued.
Santosha is contentment with whatever one obtains of its own accord without effort.
Astikya is firm, unshakable belief in the existence of God, in the words of the Guru, in the truths inculcated in the Vedas and the merits or demerits of actions stated in the Vedas.
Dana is charity, the distribution of money, cloth, food, grains, etc., earned lawfully at the sweat of the brow, with faith, to deserving persons without expectation of fruits and without the idea of agency.
Isvara Pujana is the worshiping of Lord Hari, Siva, Krishna or Rama with pure love, intense faith and single-minded devotion.
Siddhanta Sravana is the inquiry into the right significance of Vedanta. It is the study and reflection of the nature of Brahman and the right significance of ‘Tat Tvam Asi’ Mahavakya.
Hrih is the feeling of shame one experiences when they do certain actions which are not in accordance with the injunctions of the Vedas and rules of society.
Mati is the faith in the paths prescribed by the Vedas for the attainment of God-consciousness or Self Realisation.
Japa is the repetition of the Mantra into which one is duly initiated by the Guru or spiritual guide and which is not contrary to the rules of the Vedas.
Vrata is the regular observance of or refraining from the actions prescribed or prohibited by the Vedas. The practice of Krichara, Chandrayana Vratas come under this heading. Krichara Vrata is fasting for 12 days. The observer of the Vrata drinks only some water. Many sins are destroyed by the practice of this Vrata.
Swami Vishnudevananda writes about Saucha/Purity in his Meditation and Mantras book:
Aside from Saucha, purification and cleanliness, one should cultivate indifference toward the body. Cleanliness means internal as well as external purification. A proper diet based on vegetarianism and natural foods, specialized yogic cleansing techniques and the Hatha Yoga exercises keep the body internally pure and free from obstructions.
Cleanliness also extends to the mind. Only when the mind is purified of all unsavoury thoughts can it be a pure mirror for the reflection of the higher Self.
Patangali Yoga Sutras Chapter 2.41
Sattvasuddhi-saumanasyaikagryendriva-jayatma-darsana-yogyatvani ca.
From purification also come clarity of mind, cheerfulness, one pointed mind, control of the senses and fitness, for realization of the Self.
From internal and external cleansing come all of the above, that is, a prevailing sense of Sattwa – the quality of purity and light.