The Buddha explains the eight grounds for laziness and the eight grounds for arousing energy.
Kusītārambhavatthu sutta - Grounds for Laziness and Arousing Energy
Grounds for Laziness
"Bhikkhus, there are eight grounds of laziness. What are these eight?
1 Here, bhikkhus, a bhikkhu has work to be done. He thinks, 'I have work to do, but doing this work will make my body tired. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the first ground of laziness.
2 Again, bhikkhus, a bhikkhu has completed some work. He thinks, 'I have done my work, but doing it has made my body tired. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the second ground of laziness.
3 Again, bhikkhus, a bhikkhu has a path to travel. He thinks, 'I have a path to travel, but traveling it will make my body tired. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the third ground of laziness.
4 Again, bhikkhus, a bhikkhu has traveled a path. He thinks, 'I have traveled the path, but doing so has made my body tired. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the fourth ground of laziness.
5 Again, bhikkhus, a bhikkhu, while going for alms in a village or town, does not obtain sufficient food, whether coarse or excellent. He thinks, 'While going for alms in a village or town, I did not obtain sufficient food, whether coarse or excellent. My body is tired and unfit for work. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the fifth ground of laziness.
6 Again, bhikkhus, a bhikkhu, while going for alms in a village or town, obtains sufficient food, whether coarse or excellent. He thinks, 'While going for alms in a village or town, I obtained sufficient food, whether coarse or excellent. My body feels heavy, unfit for work, and overstuffed. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the sixth ground of laziness.
7 Again, bhikkhus, a slight illness arises in a bhikkhu. He thinks, 'This slight illness has arisen in me. It is suitable to lie down.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the seventh ground of laziness.
8 Again, bhikkhus, a bhikkhu has recently recovered from an illness. He thinks, 'I have recently recovered from my illness. My body is weak and unfit for work. Let me lie down instead.' He then lies down, not arousing energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the eighth ground of laziness.
Grounds for Arousing Energy
Bhikkhus, there are eight grounds for arousing energy. What are these eight?
1 Here, bhikkhus, a bhikkhu has work to be done. He thinks, 'I have work to do. While doing this work, it is not easy to keep the teachings of the Buddhas in mind. Therefore, let me immediately arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized. This, bhikkhus, is the first ground for arousing energy.
2 Again, bhikkhus, a bhikkhu has completed some work. He thinks, 'I have done my work, but while doing it, I could not pay attention to the teachings of the Buddhas. Therefore, let me arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the second ground for arousing energy.
3 Again, bhikkhus, a bhikkhu has a path to travel. He thinks, 'I have a path to travel, but while traveling it, it is not easy to keep the teachings of the Buddhas in mind. Therefore, let me arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the third ground for arousing energy.
4 Again, bhikkhus, a bhikkhu has traveled a path. He thinks, 'I have traveled the path, but while doing so, I could not keep the teachings of the Buddhas in mind. Therefore, let me arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the fourth ground for arousing energy.
5 Again, bhikkhus, a bhikkhu, while going for alms in a village or town, does not obtain sufficient food, whether coarse or excellent. He thinks, 'While going for alms in a village or town, I did not obtain sufficient food, whether coarse or excellent. My body is light and fit for work. Therefore, let me arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the fifth ground for arousing energy.
6 Again, bhikkhus, a bhikkhu, while going for alms in a village or town, obtains sufficient food, whether coarse or excellent. He thinks, 'While going for alms in a village or town, I obtained sufficient food, whether coarse or excellent. My body is strong and fit for work. Therefore, let me arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the sixth ground for arousing energy.
7 Again, bhikkhus, a slight illness arises in a bhikkhu. He thinks, 'This slight illness has arisen in me. There is a possibility that it might worsen. Therefore, let me immediately arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the seventh ground for arousing energy.
8 Again, bhikkhus, a bhikkhu has recently recovered from an illness. He thinks, 'I have recently recovered from my illness. There is a possibility that it might relapse. Therefore, let me immediately arouse energy for the attainment of what has not yet been achieved, for realizing what has not yet been realized.' He then arouses energy. This, bhikkhus, is the eighth ground for arousing energy.
These, bhikkhus, are the eight grounds for arousing energy.