18.7 Obligatory acts consist of daily, and occasional ceremonies like the five great sacrifices; their abandonment is not proper, for without actions even the sustenance of the body would be impossible, as already stated:  'From no-work, not even the body can be sustained' (3.8). The sustenance of the body by eating the sacrificial remnants produces perfect knowledge. Otherwise, as declared in the statement, 'But the sinful ones eat sin' (3.13). The satisfaction that comes by eating food which is not the remnant of sacrifice and which is therefore of the form of sin, is productive of erroneous knowledge in the mind. For, as declared in the Sruti, 'The mind consists of food' (Cha. U., 6.5.4), the mind is sustained by food. Also, there is the Sruti text, 'When the food is pure, the mind becomes pure; when the mind is pure, remembrance becomes firmly fixed; and when remembrance is acired, there is release from all knots of the heart' (Ibid., 7.26.2). It is therefore proved by the Sruti that knowledge of the form of direct perception of Brahman, is dependent on the purity of food. Hence the great sacrifices and such other obligatory and occasional rites are worthy of adoption till one's death, as they help in the knowledge of the Brahman. The renunciation of these is therefore not proper. Thus, the relinishment of these acts which produce knowledge through the delusion that they bind the self, is rooted in Tamas.

Tamasika renunciation has its roots in Tamas. Since such renunciation has its roots in ignorance which is the effect of Tamas, such renunciation is said to have its roots in Tamas. For Tamas is the root of ignorance as has been stated:  'From Tamas arise negligence and delusion, and also, ignorance' (14.17). Ignorance is erroneous knowledge which is antagonistic to right knowledge. So, it will be taught, 'That reason which, enveloped in Tamas, regards wrong as right, and which reverses every value, O Arjuna, is Tamasika' (18.32). It is for this reason that the renunciation of obligatory and occasional actions are said to have their roots in erroneous knowledge.