Mbh 12.15.2c

The very ascetics cannot support their lives without killing creatures. In water, on earth, and fruits, there are innumerable creatures. It is not true that one does not slaughter them. What higher duty is there than supporting one's life?[36] There are many creatures that are so minute that their existence can only be inferred. With the falling of the eyelids alone, they are destroyed. There are men who subduing wrath and pride betake themselves to ascetic courses of life and leaving village and towns repair to the woods. Arrived there, those men may be seen to be so stupefied as to adopt the domestic mode of life once more. Others may be seen, who (in the observance of domesticity) tilling the soil, uprooting herbs, cutting off trees and killing birds and animals, perform sacrifices and at last attain to heaven. O son of Kunti, I have no doubt in this that the acts of all creatures become crowned with success only when the policy of chastisement is properly applied. If chastisement were abolished from the world, creatures would soon be destroyed. Like fishes in the water, stronger animals prey on the weaker. This truth was formerly spoken by Brahmana himself, viz., that chastisement, properly applied upholds creatures. Behold, the very fires, when extinguished, blaze up again, in fright, when blown. This is due to the fear of force or chastisement. If there were no chastisement in the world distinguishing the good from the bad, then the whole world would have been enveloped in utter darkness and all things would have been confounded. Even they that are breakers of rules, that are atheists and scoffers of the Vedas, afflicted by chastisement, soon become disposed to observe rules and restrictions.[37] Everyone in this world is kept straight by chastisement. A person naturally pure and righteous is scarce. Yielding to the fear of chastisement, man becomes disposed to observe rules and restraints.