At Sāvatthī.

“Mendicants, transmigration has no known beginning. No first point is found of sentient beings roaming and transmigrating, hindered by ignorance and fettered by craving. What do you think? Which is more: the flow of tears you’ve shed while roaming and transmigrating for such a very long time—weeping and wailing from being united with the unloved and separated from the loved—or the water in the four oceans?”

“As we understand the Buddha’s teaching, the flow of tears we’ve shed while roaming and transmigrating is more than the water in the four oceans.”

“Good, good, mendicants! It’s good that you understand my teaching like this. The flow of tears you’ve shed while roaming and transmigrating is indeed more than the water in the four oceans. For a long time you’ve undergone the death of a mother … father … brother … sister … son … daughter … loss of relatives … loss of wealth … or loss through illness. From being united with the unloved and separated from the loved, the flow of tears you’ve shed while roaming and transmigrating is indeed more than the water in the four oceans.

Why is that? Transmigration has no known beginning. … This is quite enough for you to become disillusioned, dispassionate, and freed regarding all conditions.”