Manjushri declared, "It is because of the tathagatagarbha *
that the Buddhas refrain from eating meat."
And the Lord added:
it is, Manjushri. There is not a single being, wandering in the
chain of lives in endless and beginning less samsara, that has not
been your mother or your sister. An individual, born as a dog, may
afterward become your father. Each and every being is like an actor
playing on the stage of life. One’s flesh and the flesh of
others is the same flesh. Therefore the Enlightened Ones eat no
meat. Moreover, Mahjushri, the dharmadhatu **
is the common nature of all beings, therefore Buddhas
refrain from eating meat."
also said, "There are, Lord, other, quite ordinary beings who
also abstain from meat."
worldly people do," the Lord replied, "that is in harmony
with the Buddha's word should be considered as the teachings of
the Buddha himself."
Tathagatagarbha (Skt.) is the 'embryonic Buddha', referring to the
potential of all beings to become a Buddha.
** Dharmadhatu (Skt.) is that from which all dharma (phenomena)
FB, p. 64-65)