One day the Blessed One took up a little bit of soil in his fingernail and asked the monks, “What do you think, monks, which is more: the little bit of soil in my fingernail or the great earth?”
“Bhante, the great earth is more. The little bit of soil that the Blessed One has taken up in his fingernail is very small. Compared to the great earth, the little bit of soil that the Blessed One has taken up in his fingernail is not knowable, is beyond comparison, and not even an amount of a fraction.”
“So too, monks, when human beings pass away, the amount of beings reborn as humans in their next life is extremely few. However, when human beings pass away, the amount of beings reborn as hell beings in their next life is extremely large. What is the reason for this? It is because, monks, they have not understood the Four Noble Truths. What are those Four Noble Truths? The Noble Truth of suffering, the Noble Truth of the cause of suffering, the Noble Truth of the end of suffering, and the Noble Truth of the path that leads to the end of suffering.”
“Therefore, monks, you should put an effort to understand: ‘This is suffering.’ You should put an effort to understand: ‘This is the cause of suffering.’ You should put an effort to understand: ‘This is the end of suffering.’ You should put an effort to understand: ‘This is the path that leads to the end of suffering.’”