Bhagavad Gita Chapter 03, Text 13

Bg 3.13

yajna-sistasinah santo
mucyante sarva-kilbisaih
bhunjate te tv agham papa
ye pacanty atma-karanat

Word for word: 
yajna-sista — of food taken after performance of yajna; asinah — eaters; santah — the devotees; mucyante — get relief; sarva — all kinds of; kilbisaih — from sins; bhunjate — enjoy; te — they; tu — but; agham — grievous sins; papah — sinners; ye — who; pacanti — prepare food; atma-karanat — for sense enjoyment.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
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.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The devotees of the Supreme Lord, or the persons who are in Krishna consciousness, are called santas, and they are always in love with the Lord as it is described in the Brahma-samhita (5.38): premanjana-cchurita-bhakti-vilocanena santah sadaiva hrdayesu vilokayanti. The santas, being always in a compact of love with the Supreme Personality of Godhead, Govinda (the giver of all pleasures), or Mukunda (the giver of liberation), or Krishna (the all-attractive person), cannot accept anything without first offering it to the Supreme Person. Therefore, such devotees always perform yajnas in different modes of devotional service, such as sravanam, kirtanam, smaranam, arcanam, etc., and these performances of yajnas keep them always aloof from all kinds of contamination of sinful association in the material world. 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? It is not possible. Therefore, in order for people to become happy in all respects, they must be taught to perform the easy process of sankirtana-yajna, in full Krishna consciousness. Otherwise, there can be no peace or happiness in the world.