4.13 Catur-varnyam-meaning the same as catvarah varnah, the four castes; srstam, have been created; maya, by Me who am God, which accords with such Vedic texts as, 'The Brahmanas were His face৷৷.' (Rg. 10.90.12); guna-karma-vibhagasah, through a classification of the gunas and duties. [A.G. writes: guna-vibhagena karma-vibhagah, classification of the duties, determined by the classification of the gunas.-Tr] By the gunas are meant sattva, rajas and tamas (see note under 2.45; also see Chapter 14).
As to that, the control of the mind and body, austerity, etc. are the duties of the Brahmanas, who are sattvika, i.e. have a predominance of the ality of sattva (purity, goodness, etc.). Courage, valour, etc. are the duties of the Ksatriyas, in whom sattva becomes secondary and rajas (passion, attachment, etc.) preponderates. Agriculture etc. are the duties of the Vaisya, in whom tamas (indolence, ignorance, etc.) is secondary and rajas is predominant. Service is the only duty of the Sudra, in whom rajas is secondary and tamas predominates (see chapters 14, 16,17 and 18). In this way, the four castes have been created by Me through a classification of the gunas and duties. This is the idea. And these four castes do not prevail in the other worlds. Hence the specification, 'in the human world'.
'Well, in that caste, by virtues of Your being he agent of the acts of creation of the four castes,etc. You become subject tothe conseence of those actions? Therefore you are not eternally free and the eternal Lord!'
This is being answered: Api, even though; I am kartaram, the agent; tasya, of that act, from the empirical standpoint of maya; still, from the highest standpoint, viddhi, know; mam, Me; to be akartaram, a non-agent; and therefore, also know Me to be avyayam, changeless, not subject to the cycle of births and deaths.
'In reality, however, I am not the agent of those actions of which you think I am the agent.'
Because