The Great Vow is setting up and defining the goal. Without a goal we may go in circles or backwards. But if we have a view of the proper goal, whether we travel fast or slow, eventually we reach our destination. This is the first aspect of the Great Vow.
The second aspect is that the Great Vow helps us overcome selfishness. We make vows not for our own sake but for the sake of all sentient beings.
Shakyamuni became the Buddha because he saw that all life is full of suffering—birth, aging, sickness, and death. He also saw that in the animal realm the stronger preyed on the weaker. He realized that samsara, the cycle of birth and death, is characterized by suffering. To him the question of helping sentient beings to liberate themselves from this suffering became very crucial. He decided to give up his royal position and dedicate himself to finding a way to help all sentient beings.
Therefore, he made a vow to leave home and become an ascetic. After practicing many methods for many years, he became supremely enlightened, and attained Buddhahood. If he had been selfishly motivated, after his liberation Shakyamuni Buddha would not have stayed behind to teach others. But within a few days he started teaching, and these teachings have been handed down until today.
His vow helped him to attain Buddhahood. This Great Vow is very different from selfishness. It is not just thinking, "I want to become enlightened." That attitude is great for developing faith in one's self. But by the time one develops the Great Vow, one should gradually drop this self-centeredness.
At this point the expanded, large sense of self appears. The Great Vow is needed to transcend the small self. If we are not willing to leave behind this small self, it is impossible to get enlightened. That can only come after you have let go of the self and perceive wu (emptiness), or no-self.
It is for this reason that all Buddhas made Great Vows when they began their practice. The most common vows we make are the Four Great Vows:
I vow to deliver all sentient beings,
I vow to cut off all vexations.
I vow to master all Dharma methods.
I vow to attain supreme Buddhahood.
The first vow is the most important. If you think only of helping all sentient beings, naturally your own vexations will be lessened. If you have only helping sentient beings in mind, naturally you will learn all the Dharma methods. Finally, if you persist in helping sentient beings until there is no self, at that time sentient beings also disappear.
Then you will have attained Buddhahood, for at that point there is no discrimination, no sentient beings, and no self. These vows are made every day by all Buddhas and bodhisattvas and anyone who wishes to practice seriously. Of course we cannot accomplish these vows on retreat, but we can derive great energy from them.
The power of the vows pulls us ahead, because they are always kept in front of us.
Other than these Great Vows, another vow that I emphasize is one that should be made before each sitting. Before his enlightenment, when Shakyamuni sat down on his pile of dry grass, he made a vow. He said, "I will not rise until I reach supreme awakening, though my body becomes as dust."
In later ages, his seat was considered the "diamond seat," in reference to the unmoving nature of his mind. Each time we sit, though we may not accomplish the diamond seat, it should at least be a stone seat. It should not be a seat of whipped cream. Before each sitting, we should vow to sit until we get to a certain state.
Will such vows always be accomplished? Not often. Your legs really hurt, your mind is scattered, you can't meditate anymore. What can you do? You give up. Then you tell yourself, this time I failed my vow. But next time, I will make the same vow, and do better. With each sitting, making such a vow, your sittings improve, your faith and energy grow.
Great Angry Determination is not a kind of hate, but rather, has to do with the will. It is also different from the Great Vow. Great Angry Determination is the persistance to practice hard, to go forward continuously. Basically, everyone has great inertia. When they run into difficulties, they can be disillusioned and disappointed. When tired they want to sleep. Practice is like rowing a boat upstream.
If you don't row continuously, you will drift backward. When you cook rice, you cook it until it is ready, in one cooking. If you cook it for a while, turn off the fire, then later, turn on the fire again, and so on, you definitely won't get good rice. Just like in practice. You do it continuously, not interruptedly.