Living beings are born under a combination of conditions. When the cycle of twelve conditioned causes runs its course, people come into being. Ants and microbes are also living beings. We don't need to look outside, for there are innumerable living beings right within our own natures. Modern science has confirmed the existence of countless germs and microorganisms in the human body. The pork, beef, and fish that people eat also comes from living beings. Meat contains many germs, and the seeds of these germs remain in the stomachs of people who eat meat.
When you eat a lot of the flesh of a particular kind of living being, you deepen your affinities with it and become inextricably related to it. If you eat a lot of pork and ham, you may be reborn as a pig. If you eat a lot of beef, you may be reborn as a cow. But if you eat a lot of rice, will you turn into rice? No, since rice is insentient. If you eat sentient beings, you will be reborn among them. But if you eat insentient things, you can nurture your Dharma-body and wisdom-life. When you refrain from eating a certain species of living being, you are taking that species across. That is, you are taking them across the sea of suffering to reach the other shore of Nirvana. People who understand this should not eat the flesh of living beings.
Once upon a time, a man who ate meat went before King Yama after he died. All the living beings whose flesh he had eaten in his life went to settle their accounts with him. The meat-eater defended himself. “Although I was the one who ate the meat, I'm not to blame. The meat-vendor is the guilty one.” King Yama sent for the meat-vendor, who argued, “I sell meat only because people want to buy it. If there was no demand for it, there would be no reason for me to sell it.” And so the meat-vendor and the meat-eater quarrelled with each other, and they ended up blaming the butcher.
When King Yama called in the butcher, he said, “I slaughter pigs, it's true, but I do it only because people buy it and eat it. If no one bought or ate meat, I would never kill them.” Each of them presented their own arguments to justify their offenses. In the end, King Yama still judged that the meat-eater should pay his debt of blood.
From this story, we can see that whenever we consume the flesh of any species of living being, we create a bond of enmity with that species which cannot be dissolved.
In the Chinese character for “meat”（肉），
there are two people（人）；
The one inside has been caught
by the one outside.
So when living beings eat the flesh of
other living beings,
Stop to think about it: Aren't they just
people eating people?
A passage in the Shurangama Sutra explains how sheep can be reborn as people. If sheep can become people, so can pigs and cows. If you haven't opened the Celestial Eye, you cannot see these things and you think pigs are just pigs and sheep are just sheep. People who eat a lot of meat are really smothering their own natures, losing their souls, and making themselves stupid. If you want to save living beings, you must first stop eating their flesh. Start by saving the living beings within your own nature. To truly save beings, you must be detached from appearances and free of attachments.