Bhagavad Gita, Chapter 18, Verse 41

ब्राह्मणक्षत्रियविशां शूद्राणां च परन्तप । कर्माणि प्रविभक्तानि स्वभावप्रभवैर्गुणैः

brāhmaṇakṣatriyaviśāṃ śūdrāṇāṃ ca parantapa | karmāṇi pravibhaktāni svabhāvaprabhavairguṇaiḥ

Translation

Of Brāhmaṇas and Kṣatriyas and Vaiśyas, as also of Śūdras, O Parantapa, the duties are divided according to the qualities born of nature.

— Alladi Mahadeva Sastri

Word meanings

brāhmaṇakṣatriyaviśām

of Brāhmaṇas, and, of Kshattriyas, and, of Vaishyas, and

śūdrāṇām

of Shūdras

ca

and

parantapa

O Parantapa

karmāṇi

actions

pravibhaktāni

(are) distributed

svabhāvaprabhavaiḥ

by own-nature-produced

guṇaiḥ

by qualities

Śaṅkarācārya's commentary

Śūdras are separated from others because Śūdras are of one birth and are debarred from the study of the Vedas. The duties are allotted to each class. Nature (svabhāva) is the Īśvara's Prakṛti, the Māyā made up of the three guṇas. The source of the Brāhmaṇa's nature is the guṇa of Sattva; the source of the Kṣatriya's nature is Rajas and Sattva, the latter subordinate to the former; the source of the Vaiśya's nature is Rajas and Tamas, the latter subordinate to the former; the source of the Śūdra's nature is Tamas and Rajas, the latter subordinate to the former. The characteristic features of their nature are serenity, lordliness, activity, and dullness respectively. By the śāstra too are the duties — such as serenity — assigned to the Brāhmaṇas etc. only in accordance with their respective guṇas, not independently of them.