Dama is one of the qualities characterizing the enlightened one (Bhagavad Gita X. 4), and is distinguished from sama, denoting the restraint of the thinking faculty. Dama is self restraint by way of controlling the five external senses of touch, taste, sight, smell and hearing.
Dama is also used in the sense of driving out evil thoughts from one’s mind. Since the good and bad deeds of a person arise from the contact of the senses with the external objects, the senses have to be withdrawn from the materials and the mind turned away from evil deeds or propensities.
Dama is a primary step in the realization of the Self.
Dama is one of the ten characteristics of dharma (righteousness) enjoined on the ascetics (Manu Smriti VI.92), and has the sense of eschewing haughtiness about one’s learning.
Brihadaranyaka Upanishad (v.2) contains a fable according to which gods, men and demons, the three descendants of Prajapati, were with him for some time seeking instruction from him. He uttered da thrice. Gods understood the syllable to mean that they should exercise greater dama (self control). Men took it to mean danam, suggesting they should be charitable. Demons took it as implying daya, meaning that they should be more compassionate.
In the works of dharma the word dama means punishment also. The danda (sceptre) is known as dama because it restrains the offender from an unsocial act.
Adi Shankaracharya thinks the first word atha in the first aphorism athato brahmajnasa (Brahmasutra I.1-1) indicates the qualifications required for a spiritual aspirant. These are: capacity to discriminate between the permanent and the impermanent; sense of detachment; sama (mind control); dama (sense control); titiksha (forbearance); uparati (withdrawal); Shraddha (faith) and Samadhi (concentration); mukuksha (yearning to be released). From this, the control of the sense organs is a prerequisite to a sadhaka, and it helps one to overcome the internal enemies of desire, anger, greed, infatuation, passion and competitive spirit.