Srimad Bhagvata Mahapurana: Book 11: Chapter 25: Verses 1-15
The glorious Lord began again: (Now) learn from Me, 0 jewel among men, as I tell you, how and by which of the (three) Gunas (modes of Prakrti), working independently of one another, is man affected. Control of the mind and the senses, forbearance, sound judgment, askesis (in the form of strict adherence to one's prescribed course of conduct) truthfulness, compassion, retentive power, contentment, self-abnegation, absence of thirst for the pleasures of sense, belief in God, life after death and so on, modesty and shrinking from unrighteous acts, liberality etc., and remaining. delighted in the self (forming the first group); hankering after the pleasures of sense, (self-centred) activity, arrogance, insatiability, inflexibility, seeking after blessings (from gods etc.), differentiation (between one's own self and others), self-gratification, bellicosity through arrogance, love of praise, jocularity, display of valour and exertion through might (forming the second group); and intolerance, stinginess, mendacity, malevolence, mendicancy, hypocrisy, languor, discord, grief and delusion, gloom and wretchedness, drowsiness, expectation, fear and indolence (forming the third group);- these are severally the effects of Sattva, Rajas and Tamas, enumerated (by Me) almost exhaustively, Now hear (from Me) the combined effect (of the three Gunas).The notion which is expressed in the words "I am (tranquil, passionate or angry)" and "These (traits such as tranquillity, lust and anger) belong to me" is as a matter of fact a combined effect (of the three Gunas); and whatever is done with the mind, the objects of the senses (viz., sound, touch, sight, taste and smell), the senses (themselves) and the vital airs (conjointly) is also a combined effect of the three Gunas (since all these instruments are themselves a product of the three Gunas and all action is preceded by the feeling of I-ness and my-ness). When a man is keenly devoted to religious merit, material possessions and sense-gratification, this (keen devotion of his also) is a combined effect of the three Gunas (inasmuch as Dharma etc., are themselves a product of the three Gunas) and conduce to reverence, wealth and sense-gratification respectively. When a man is devoted to holy rites performed with interested motives and when he sticks to the life of a householder and later on adheres to his (obligatory and occasional) duty, such devotion etc., (as well) on his part is indeed a combined effect of the three Gunas (inasmuch as devotion to holy rites performed with interested motives, attachment to the household and devotion to one's allotted duty are products of Rajas,Tamas and Sattva respectively). From virtues like self-control one should conclude a man to be endowed (predominantly) with Sattva; from passion etc., one should know him to be (principally) full of Rajas and from anger and other characteristics he should infer him to be full of Tamas. When a person worships Me disinterestedly with devotion through (the performance of) his duties one should know that man or woman too to be endowed with a Sattvika disposition. When a man seeking the pleasures of sense worships Me through his actions, one should know him to be of Rajasika disposition; and when he does so expecting injury to others (his adversaries etc.), one should know him to be Tamasika (by nature). The Gunas (modes of Prakrti), viz., Sattva, Rajas and Tamas, affect the Jiva (embodied soul) alone and not Me, inasmuch as they appear (only) in the mind of the former and because it is the diva alone that is bound (to this mundane existence) through them, getting attached to the elements (in the form of the body, senses, mind and the objects of the senses). When Sattva, which is illuminating, transparent and tranquil, prevails over the other two Gunas (viz., Rajas and Tamas), a man is characterized by wisdom, piety and happiness etc., respectively. When (on the other hand) Rajas-which gives rise to attachment and the notion of diversity and spurs one to activity-gets the better of Tamas and Sattva, then one is sized with a craving for glory and fortune and is characterized by unhappiness and activity. When (however) Tamas-which perverts one's judgment, clouds one's vision and induces dullness-dominates Rajas and Sattva, a man is characterized by grief, infatuation and violence (as a result of perverted judgment), (excessive) sleep (through obscurity of the mind) and by expectation of help from others (through indolence caused by dullness).