|Chapter 3: Karma-yoga|
bhunjate te tv agham papa
ye pacanty atma-karanat
The devotees of the Lord are released from all kinds of sins because they eat food which is offered first for sacrifice. Others, who prepare food for personal sense enjoyment, verily eat only sin.
This verse addresses a very important point that modern day vegetarians often wrestle with. Since it is a known fact that plants like animals also have consiousness and life. So how does being a vegetarian lead to more piety?
Krishna answers this question here. In offering food to Lord Vishnu, all the sins of killing a living entity is taken away and the food is now sanctified and becomes prasadam. However only plants can be offered to Lord Vishnu – remenants of animals is not acceptable. People who eat food that has not been offered, whether it is from plant or animal, generates sinful reactions since they are invariable accompanied by the sin of killing that life form. Srila Prabhupada comments, "Others, who prepare food for self or sense gratification, are not only thieves but also the eaters of all kinds of sins. How can a person be happy if he is both a thief and sinful?"
Please read the Sanskrit Verse and the Prabhupada's Purport.