The Buddha describes four noble thoroughbred horses, each stirred and driven to urgency by progressively stronger stimuli. He draws a parallel to four noble thoroughbred persons, who likewise respond to increasingly intense circumstances with urgency and determination, leading them to the highest truth.
Patoda sutta - Whip
"Bhikkhus, these four noble thoroughbred horses are found in the world. What four?
1 Here, bhikkhus, a certain noble thoroughbred horse, seeing the shadow of the whip, is stirred and experiences a sense of urgency: 'What will the horse trainer make me do today? How will I act accordingly?' Such, bhikkhus, is one kind of noble thoroughbred horse present here. This, bhikkhus, is the first kind of noble thoroughbred horse found in the world.
2 Furthermore, bhikkhus, here a certain noble thoroughbred horse is not stirred nor experiences a sense of urgency upon seeing the shadow of the whip, but it is stirred and experiences a sense of urgency when its hairs are struck by the whip: 'What will the horse trainer make me do today? How will I act accordingly?' Such, bhikkhus, is also one kind of noble thoroughbred horse present here. This, bhikkhus, is the second kind of noble thoroughbred horse found in the world.
3 Furthermore, bhikkhus, here a certain noble thoroughbred horse is not stirred nor experiences a sense of urgency upon seeing the shadow of the whip, nor when its hairs are struck by the whip, but it is stirred and experiences a sense of urgency when its hide is struck by the whip: 'What will the horse trainer make me do today? How will I act accordingly?' Such, bhikkhus, is also one kind of noble thoroughbred horse present here. This, bhikkhus, is the third kind of noble thoroughbred horse found in the world.
4 Furthermore, bhikkhus, here a certain noble thoroughbred horse is not stirred nor experiences a sense of urgency upon seeing the shadow of the whip, nor when its hairs are struck by the whip, nor when its hide is struck by the whip, but it is stirred and experiences a sense of urgency when its bones are struck by the whip: 'What will the horse trainer make me do today? How will I act accordingly?' Such, bhikkhus, is also one kind of noble thoroughbred horse present here. This, bhikkhus, is the fourth kind of noble thoroughbred horse found in the world.
Bhikkhus, these are the four noble thoroughbred horses found in the world.
In the same way, bhikkhus, these four noble thoroughbred persons are found in the world. What four?
1 Here, bhikkhus, a certain noble thoroughbred person hears: 'In such and such a village or town, some woman or man is afflicted or has passed away.' Upon hearing this, they are stirred and experience a sense of urgency. Stirred, they strive prudently. Resolutely, they realize the highest truth through direct experience with the body and penetrating it deeply with wisdom, they see it. I say that this noble thoroughbred person is similar to the noble thoroughbred horse that is stirred and experiences a sense of urgency upon seeing the shadow of the whip. Such, bhikkhus, is one kind of noble thoroughbred person present here. This, bhikkhus, is the first kind of noble thoroughbred person found in the world.
2 Furthermore, bhikkhus, here a certain noble thoroughbred person does not hear: 'In such and such a village or town, some woman or man is afflicted or has passed away.' Rather, he himself sees some woman or man is afflicted or has passed away. Upon seeing this, he is stirred and experiences a sense of urgency. Stirred, they strive prudently. Resolutely, they realize the highest truth through direct experience with the body and penetrating it deeply with wisdom, they see it. I say that this noble thoroughbred person is similar to the noble thoroughbred horse that is stirred and experiences a sense of urgency when its hairs are struck by the whip. Such, bhikkhus, is also one kind of noble thoroughbred person present here. This, bhikkhus, is the second kind of noble thoroughbred person found in the world.
3 Furthermore, bhikkhus, here a certain noble thoroughbred person does not hear: 'In such and such a village or town, some woman or man is afflicted or has passed away,' nor do they personally see some woman or man who is afflicted or has passed away. Rather, a relative or family member of theirs is afflicted or has passed away. He is stirred by this and experiences a sense of urgency. Stirred, they strive prudently. Resolutely, they realize the highest truth through direct experience with the body and penetrating it deeply with wisdom, they see it. I say that this noble thoroughbred person is similar to the noble thoroughbred horse that is stirred and experiences a sense of urgency when its hide is struck by the whip. Such, bhikkhus, is also one kind of noble thoroughbred person present here. This, bhikkhus, is the third kind of noble thoroughbred person found in the world.
4 Furthermore, bhikkhus, here a certain noble thoroughbred person does not hear: 'In such and such a village or town, some woman or man is afflicted or has passed away,' nor do they personally see some or man who is afflicted or has passed away, nor is any relative or family member of theirs afflicted or has passed away. But rather, they are struck with painful bodily feelings—sharp, harsh, bitter, unpleasant, disagreeable, and life-threatening. They are stirred by this and experience a sense of urgency. Stirred, they strive prudently. Resolutely, they realize the highest truth through direct experience with the body, and penetrating it deeply with wisdom, they see it. I say that this noble thoroughbred person is similar to the noble thoroughbred horse that is stirred and experiences a sense of urgency when its bones are struck by the whip. Such, bhikkhus, is also one kind of noble thoroughbred person present here. This, bhikkhus, is the fourth kind of noble thoroughbred person found in the world.
Bhikkhus, these are the four noble thoroughbred persons found in the world."