Bhagavad Gita Chapter 3 Verse 21
भगवद् गीता अध्याय 3 श्लोक 21

यद्यदाचरति श्रेष्ठस्तत्तदेवेतरो जनः।
स यत्प्रमाणं कुरुते लोकस्तदनुवर्तते।।3.21।।



हिंदी अनुवाद - स्वामी रामसुख दास जी ( भगवद् गीता 3.21)
।।3.21।।श्रेष्ठ मनुष्य जोजो आचरण करता है दूसरे मनुष्य वैसावैसा ही आचरण करते हैं। वह जो कुछ प्रमाण देता है दूसरे मनुष्य उसीके अनुसार आचरण करते हैं।


Shri Vaishnava Sampradaya - Commentary

So understanding that the whole  Earth  benefits  from  the  performance  of
prescribed  Vedic  activities,  one  should  act  altruistically   not   for
themselves but for the welfare of  the  world.  This  is  the  meaning  Lord
Krishna is conveying. The word sresthah means great  personality  expert  in
the conclusions   of  the  Vedas.  Whatever  actions  such  a  great  person
performs others will try to follow.  It  may  be  that  a  certain  activity
should be performed on a special day. The common people  will  wait  to  see
how a great person takes the initiative on such  an  action  and  then  they
will follow suit. Hence the great personalities  should  always  act  in  an
exemplary manner to set the  standard  for  the  world.  In  this  way  they
inspire everyone to  perform  prescribed  Vedic  actions  according  to  the
qualification of ones varna or caste in life and ones asrama or  stage  in
life. If one fails to do this by neglect or  omission  one  commits  sin  by
omitting to help benefit the welfare of the world by their example  and  the
consequence will be one will fall down from the  path  they  achieved  after
many lifetimes.