Let him not destroy, or cause to be destroyed,
any life at all, or sanction the acts of those who do so.
Let him refrain even from hurting any sentient being,
both those that are strong and those that tremble in the world.
If we fail to understand the universality of this injunction, the Buddha clarifies (Kshudraka Agama):
Whether they be creatures of the land or air,
whoever harms here any sentient being,
who has no compassion for all that live,
let such a one be known as depraved.