Bhagavad Gita Chapter 18 Verse 41
भगवद् गीता अध्याय 18 श्लोक 41

ब्राह्मणक्षत्रियविशां शूद्राणां च परंतप।
कर्माणि प्रविभक्तानि स्वभावप्रभवैर्गुणैः।।18.41।।



हिंदी अनुवाद - स्वामी तेजोमयानंद
।।18.41।। हे परन्तप ब्राह्मणों? क्षत्रियों? वैश्यों और शूद्रों के कर्म? स्वभाव से उत्पन्न गुणों के अनुसार विभक्त किये गये हैं।।


Kumara Vaishnava Sampradaya - Commentary
The word svabhava means ones inherent nature. This inherent nature  arises
from samskaras or past impressions and karma or reactions from past actions
and is the root cause of determining birth as a Brahmin. The three gunas or
modes of material nature arising from prakriti or the  material  substratum
pervading all existence are determined by karma and samskaras as well.  The
predominating attribute of the Brahmins or spiritual class is  sattva  guna
the mode of goodness. The predominating characteristic of the  ksatriya  or
administrative class is raja guna the mode of  passion.  The  predominating
characteristic of the vaisyas or mercantile class is tama guna  mixed  with
raja guna and the predominating characteristic of the sudras is  only  tama
guna. Duties and responsibilities vary according to position and status  in
society as assigned by the Vedic scriptures. It  is  the  Vedic  scriptures
which defines what qualities are possessed by Brahmins  and  what  are  the
duties proper to their status as well as what occupations they  may  engage
in. This Vedic directive applies to the other orders in society as well.