B.G 4.13
चातुर्वर्ण्यं मया सृष्टं गुणकर्मविभागशः। तस्य कर्तारमपि मां विद्ध्यकर्तारमव्ययम् ॥१३॥
cāturvarṇyaṁ mayā sr̥ṣṭaṁ guṇakarmavibhāgaśaḥ। tasya kartāramapi māṁ viddhyakartāramavyayam ॥13॥
The classification system of four classes, based on the duties to be performed according to one's qualities, is created by Me. Even though I am the creator of these, know Me as the non-doer, and as imperishable.
Gīta Bhāshya 4.13
Varnas are classification based on qualities. 'Brahmin', the intellectual class, is of Sātwik quality. 'Kshatriya', the warrior class, is formed by the combination of 'Sātwik' and 'Rajasic' qualities. The 'Vaisha', the business class, is formed by the combination of 'Rajasic' and 'Tamasic' qualities. The 'Shudra', the employee class, is of 'Tamasic' quality. Divisions of activities that arise due to qualities are dealt at 18.42 verse of Gita. The lord is known as 'non-doer' though He is the doer, as the nature of His actions is beyond the grasp of mortals.
Indeed, I am only the creator of the populace comprising four classes, is conveyed by the verse 'cāturvarṇyam'. Those with 'Sātwik' qualities are 'Brahmins'. Those with the combination of 'Sātwik' and 'Rājasic' qualities are 'Kshatriyas'. Those with the combination of Rājasic and Tāmasic qualities are 'Vasihyas'. Those with 'Tāmasic' qualities are 'Shūdras'. The division based on duties to be performed are stated in the verse "śamo damaḥ" (18.42), and onwards.
Due to the nature of His actions being special, though He is the doer, He is said to be non-doer. Same is stated in the Vedic testimonials:
"He is the creator of the universe, who is beyond thought!"
-(Rig 10.82.2, Visvakarma Sukta) and such others.
"Knowledge is my body and activities in the form of duties are my form."
-stated thus as well (at 6.4.46 Bhagavatam).
This topic, (regarding the lord and his qualities being beyond the grasp of the intellect and conflicting attributes existing in him without conflict,) has already been dealt with and established in previous sections.
