Bhagavad-Gita The Song Divine Chapter 17 (stanza 16-28)

Cheerfulness of mind, placidity, habit of contemplation on God, control of the mind and perfect purity of inner feelings - all this is called perfect purity of inner feelings - all this is called austerity of the mind. ………….. (16)

This austerity which is performed with supreme faith by Yogis expecting no return is called Sattvika. …………….. (17)

The austerity which is performed for the sake of renowned, honor or adoration, as well as for any other selfish gain, either in all sincerity or by way of ostentation, and yields an uncertain and momentary fruit, has been spoken of here as Rajasika. …………. (18)

Penance which is resorted to out of foolish obstinacy and is accompanied by self-mortification, or is intended to harm others, such penance has been declared as Tamasika. …………… (19)

A gift which is bestowed with a sense of duty on one form whom no return is expected, at appropriate time and place, and to a deserving person, that gift has been declared as Sattvika. ………………. (20)

A gift which is bestowed in a grudging spirit and with the object of getting a service in return or in the hope of obtaining a reward is called Rajasika. ……….. (21)

A gift which is made without good grace and in a disdainful spirit, out of time and place, and to undeserving persons, is said to be Tamasika. ………….. (22)

OM, TAT and SAT - this has been declared as the triple appellation of Brahma, who is Truth, Consciousness and Bliss. By that were the Brahmans and the Vedas as well as sacrifices created at the cosmos dawn. ………….. (23)

Therefore, acts of sacrifice, charity and austerity, as enjoined by sacred precepts, are always commenced by noble persons, used to the recitation of Vedic chants, with the invocation of the divine name "OM". …………. (24)

With the idea that all this belongs to God, who is denoted by the appellation "TAT", acts of sacrifice and austerity as well as acts of charity of various kinds, are performed by the seekers of liberation, expecting no return for them. ………………… (25)

The name of God "SAT', is used in the sense of reality and goodness. And the word 'SAT' is also used in the sense of a praiseworthy, auspicious action, Arjun. ………… (26)And steadfastness in sacrifice, austerity and charity is likewise spoken of as 'SAT' and action for the sake of God is verily termed as "SAT". ………………. (27)

An oblation which is offered, a gift given, an austerity practiced, and whatever good deed is performed, if it is without faith, it is termed as naught i.e., 'ASAT'; therefore, it is of no avail here or hereafter. …………… (28)

Thus, in the Upanishad sung by the Lord, the Science of Brahma, the scripture of Yoga, the dialogue between Sri Krishna and Arjun, ends the seventeenth chapter entitles "The Yoga of the Division of the Threefold Faith".