Shurangama Sutra sited: "A person eats a sheep. The sheep dies and becomes a person. The person dies and becomes a sheep, and it goes on that way through ten births and more. Through death after death and birth after birth, they come back to eat one another. The evil karma becomes innate and exhausts the bounds of the future. And the basis for all of this is stealing and greed.
’You owe me a life; I have to repay my debt to you.’ From these causes and conditions we pass through hundreds of thousands of aeons, in a sustained cycle of birth and death."
The Brahma Net Sutra sited: "A disciple of the Buddha must not deliberately eat meat. He should not eat the flesh of any sentient being. The meat-eater forfeits the seed of Great Compassion, severs the seed of the Buddha Nature and causes [animals and transcendental] beings to avoid him. Those who do so are guilty of countless offenses. Therefore, Bodhisattvas should not eat the flesh of any sentient beings whatsoever. If instead, he deliberately eats meat, he commits a secondary offense."
Why do people eat meat? It’s said to be for nutrition. However, you have to study how the Chinese character “meat” (肉) is written. “There are two people (人) within the character ‘meat’.” The first radical that you would write in composing the character “meat” is “mouth” (口). This mouth is open because it’s waiting to eat some meat. Where did meat come from? The two radicals that mean “people” represent somebody who is doing the eating and someone who is being eaten. The one being eaten is already in the eater’s mouth. The one doing the eating is half inside the mouth and half outside of it. This shows that while you eat meat now, you will be eaten in the future. Therefore, “The person outside is connected to the person inside.”
By eating pork, you start an incorporation with pigs. By eating beef, you start an incorporation with cows. By eating veal, you start an incorporation with lambs. Let’s all think about this: when we eat pork, our flesh turns into pork; when we eat beef, we smell like cows; when we eat veal, we smell like lambs. Not to mention meat, you smell like milk when you drink it. When you eat garlic, you smell like garlic too.
You smell like whatever you eat.
There is a good story about meat and karma. During Emperor Wu's time, there was a high monk called the Venerable Zhi. Having attained the Five Eyes and the Six Spiritual Penetrations, he could clearly discern causes and effects. One time, a rich man asked him to recite Sutras at a wedding. Upon entering the house, he sighed and said:
How strange! How very strange indeed!
The grandson marries the grandmother.
The daughter is eating her mother's flesh,
And the son is beating on a drum stretched with his father's skin.
Pigs and sheep are sitting on the couch,
And the six kinds of relatives are cooking in the pots.
People have come to offer congratulations,
But I see that it is truly suffering!
After hearing this story you should understand the horror of killing and eating meat. Thus it is best to be vegetarian.
Then, what benefits are there in being vegetarian? Well, your body is composed of the foods you eat. If you eat vegetables, you will smell like vegetables; if you eat onions, you'll smell like onions. The things you eat become part of your body. If you eat a lot of a certain thing, your body will become very similar to it.
Therefore, if you eat a lot of pork, you will become a pig. If you eat a lot of beef, you will become a cow. This accords with science and logic. The meat you eat incorporates with your body, and after you die you turn into that kind of animal. If you smell like a pig, for instance, after you die, King Yama(King of Hell) takes a sniff and says, "You smelly thing, you should be reborn as a pig." The same goes for sheep, cows, chicken, and dogs.
You can investigate this carefully. Why does a butcher of pigs have eyes resembling those of a pig? It's because he had been slaughtered as a pig many times in the past, and now he has come to seek revenge. Although he is human, his eyes are those of a pig. Cattle butchers have the eyes of a cow. The law of cause and effect is never off.
Scientists have discovered that people who eat a great deal of meat tend to get cancer. This is because the resentful and negative energy in the slaughtered animals accumulates in the bodies of the eaters. Eventually, it turns into a harmful toxin. We should cut off this relationship of causes and effects with animals and stop the vicious cycle of creating offenses against cows, sheep, chickens, and other animals. Then we will gradually lessen the inauspicious energy in the world.