SB 7.15.40
atmanam ced vijaniyat
param jñana-dhutasayah
kim icchan kasya va hetor
deham pusnati lampatah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The human form of body is meant for understanding the self and the Supreme Self, the Supreme Personality of Godhead, both of whom are transcendentally situated. If both of them can be understood when one is purified by advanced knowledge, for what reason and for whom does a foolish, greedy person maintain the body for sense gratification?
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Of course, everyone in this material world is interested in maintaining the body for sense gratification, but by cultivating knowledge one should gradually understand that the body is not the self. Both the soul and the Supersoul are transcendental to the material world. This is to be understood in the human form of life, especially when one takes sannyasa. A sannyasi, one who has understood the self, should be engaged in elevating the self and associating with the Superself. Our Krsna consciousness movement is meant for elevating the living being for promotion back home, back to Godhead. Seeking such elevation is one’s duty in the human form of life. Unless one performs this duty, why should one maintain the body? Especially if a sannyasi not only maintains the body by ordinary means but does everything to maintain the body, including even eating meat and other abominable things, he must be a lampatah, a greedy person simply engaged in sense gratification. A sannyasi must specifically remove himself from the urges of the tongue, belly and genitals, which disturb one as long as one is not fully aware that the body is separate from the soul.