The cycle of karmic retribution results in ceaseless transmigration. Sheep can become people, and humans can become sheep, as explained in the Shurangama Sutra. There are nations of sheep, nations of horses, nations of cows, of pigs, of dogs, and so forth down to the nations of bees, ants, mosquitoes, and other insects. Each of these gathers in groups of its own kind. The strong become kings, and the multitudes become nations.
The cycle of karmic retribution results in ceaseless transmigration. The karma that people create may be good or bad. If you create good karma, you will receive a pleasant reward. If you create bad karma, you will suffer and unpleasant retribution. The cycle of karmic retribution is like a turning wheel. It turns round and round and never stops. Hence sheep can become people, and humans can become sheep, as explained in the Shurangama Sutra. Not only can sheep become people, other animals can become people as well. The Shurangama Sutra tells us this very clearly.
However, when we are people, we are not sheep, so it doesn't occur to us that we could become sheep. And so we commit all kinds of evil karma without being afraid of the evil retribution that will result. There are nations of sheep. If you create evil karma, you will receive a bad retribution. If you create the karma of sheep, you will become a sheep in the future. Sheep also have their own group, which is like their nation. The sheep know their own boundaries. There are also nations of horses. Most people think of horses as being raised and bred by people, but actually, horses, like sheep, have their own species, which is like their "nation." And all the cattle should be considered to form nations of cows.
Another interpretation would be that people who like to eat mutton will be reborn as sheep in a country where sheep are raised. People who like horse m eat will receive the retribution of being horses and will become part of the society of species of horses. The term "nation" is not used in the usual sense; it refers to the animal's species or race. Cows belong to the bovine group. If people eat too much beef, they will be reborn as cows and join the race of cows. You may find this hard to believe when you are still a human being, but when you karma ripens, whether you believe it or not, you will have to undergo the retribution.
There are nations of pigs, and of dogs. And so forth down to the nations of bees, ants, mosquitoes and other insects. You may have noticed how bees always stay together with bees, ants stay with ants in their own group, and mosquitoes also gather with their own kind. They have their own nation. When one mosquito calls out, the other hear it right away. In the summertime, all the insects hum and buzz, calling out to one another. Each of these gathers in groups of its own kind. They stay together with their own race. The strong become kings and the multitudes become nations. Within each kind and species, the strongest individual is the hero and the king. When there are a lot of beings of a species, you could say they form a nation of a large group. This is a very simplistic explanations.
When one's retribution for past karma comes, it is never off by the least bit. When one contemplates with the Buddha Eye, one sees how totally inverted beings are. Suddenly, they soar to the heavens and then plummet to the hells. Suddenly they are people, suddenly they are ghosts, suddenly they are animals, suddenly they are asuras, and then, jus as suddenly, flittering, flying, crawling, and creeping things. Beings undergo these retributions in accord with their own past deeds, yet remain quite unaware that this is happening. How pitiful this is.
An ancient verse says:
Just out of a horse's belly, and into a donkey's womb,
How many times have you passed by Yama's door?
Having just gone before Lord Shakra,
Now you end up in Yama's pot.
Suddenly, they soar to the heavens and then plummet to the hells. Suddenly they are people, suddenly they are ghosts, suddenly they are animals, without quite realizing how it happened. Then just as suddenly they are asuras, beings who love to fight. The present world is filled with asuras. They are untold numbers asuras, and they quarrel and fight with one another. This is the age of fighting. Every nation wants to fight. You fight with me, and I fight with you. And then, just as suddenly, they are flittering, flying, crawling, and creeping things. They may become flittering creatures that are tinier than insects and can't fly very far, or creatures that crawl very slowly along the ground.
Beings undergo these retributions in accord with their own past deeds. Why do living beings go to the heavens, to the hells, to the human realm, become hungry ghosts, or animals, or asuras? They are reborn according to their own karma. Lord God doesn't tell them to become animals or hungry ghosts or people. God didn't tell people to become people. IF he could tell people to become people, who told him to be God? Not to mention God, even the Buddha was originally a person. He wasn't born a Buddha. Although it's said that when the Buddha was born, he said, "In the heavens above and the earth below, I alone am honored," he actually cultivated as a person for a very, very long time before he achieved Buddhahood. You can't say he's the Buddha, and that's it. The Buddha was also a person who underwent birth according to his karma. Since his pure karma ripened, he became a Buddha.
Beings are reborn according to their karma, yet remain quite unaware that this is happening. If you plant wholesome causes, they bear wholesome fruit. If you plant unwholesome causes, they bear unwholesome fruit. Beings undergo retribution for their good and evil karma without realizing what is happening. How pitiful this is. Such people are very pitiful. And so the Buddha vowed to save living beings-this kind of beings in particular. Bodhisattvas also save these living beings who don't understand what's going on. Once we, living beings, gain some understanding, we can save ourselves; we won't need the Buddhas, Bodhisattvas, or our teacher to take us across. When we are confused, our teacher leads us. When we awaken and understand, we can take ourselves across.
Disciple: What about "beings undergo these retributions in accord with their own past deeds, yet remain quite unaware that this is happening?"
Ven. Master: They themselves don't know what kind of retribution they are receiving.
King Yama is actually a Bodhisattva practicing the Bodhisattva Path. King Yama's face is as dark as iron. He is absolutely impartial and devoid of mercy. If you have committed offenses, he will send you to the hells. It's not that he orders you to go to the hells, you yourself created those offences. So, how many times have you passed by Yama's door? Having just gone before Lord Shakra in the heavens, now that you've exhausted you heavenly blessings, you end up in Yama's pot back in the hells, where you get deep-fried like a piece of dough. It's very scary! Before being liberated from birth and death, no one can escape transmigration in the six paths. Going around in the six paths is very dangerous. If you can transcend it become a Buddha, you won't have to transmigrate anymore. So as we cultivate, we ought to try our best to become Buddhas a little sooner.
From this, one should see that living beings suddenly die and are reborn, bobbing up and down like motes of dust, with no fixed location. They drift along in the wind of karma, turning in the six paths without cease.
From this, from the above description of the rounds of births and deaths in the six paths, one should see that living beings suddenly die and are reborn, bobbing up and down like motes of dust, with no fixed location. Sometimes you are born as one kind of living being and at other times you are born as another kind of living being. Suddenly you die, and just as suddenly, you are born again. You're like a speck of dust, rising and falling in an unpredictable way. They drift along in the wind of karma, turning in the six paths without cease. You are carried along by your own past karma. On good deeds you rise, on evil deeds you fall. You go round and round in the six paths and there is no end to it.