Srimad Bhagavatam Canto 04, Chapter 11, Text 10

SB 4.11.10

nayam margo hi sadhunam
hrsikesanuvartinam
yad atmanam parag grhya
pasuvad bhuta-vaisasam
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
One should not accept the body as the self and thus, like the animals, kill the bodies of others. This is especially forbidden by saintly persons, who follow the path of devotional service to the Supreme Personality of Godhead.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
 
The words sadhunam hrsikesanuvartinam are very significant. Sadhu means “a saintly person.” But who is a saintly person? A saintly person is he who follows the path of rendering service unto the Supreme Personality of Godhead, Hrsikesa. In the Narada-pañcaratra it is said, hrsikena hrsikesa-sevanam bhaktir ucyate: the process of rendering favorable service to the Supreme Personality of Godhead with one’s senses is called bhakti, or devotional service. Therefore, why should a person who is already engaged in the service of the Lord engage himself in personal sense gratification? Dhruva Maharaja is advised here by Lord Manu that since he is a pure servitor of the Lord, why should he unnecessarily engage, like the animals, in the bodily concept of life? An animal thinks that the body of another animal is his food; therefore, in the bodily concept of life, one animal attacks another. A human being, especially one who is a devotee of the Lord, should not act like this. A sadhu, a saintly devotee, is not supposed to kill animals unnecessarily.
Srimad Bhagavatam Canto 04, Chapter 11, Text 09
Srimad Bhagavatam Canto 04, Chapter 11, Text 11