At Savatthi. There the Blessed One said: "From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. What do you think, monks: Which is greater, the tears you have shed while transmigrating & wandering this long, long time — crying & weeping from being joined with what is displeasing, being separated from what is pleasing — or the water in the four great oceans?"

"As we understand the Dhamma taught to us by the Blessed One, this is the greater: the tears we have shed while transmigrating & wandering this long, long time — crying & weeping from being joined with what is displeasing, being separated from what is pleasing — not the water in the four great oceans."

"Excellent, monks. Excellent. It is excellent that you thus understand the Dhamma taught by me.

"This is the greater: the tears you have shed while transmigrating & wandering this long, long time — crying & weeping from being joined with what is displeasing, being separated from what is pleasing — not the water in the four great oceans.

"Long have you (repeatedly) experienced the death of a mother. The tears you have shed over the death of a mother while transmigrating & wandering this long, long time — crying & weeping from being joined with what is displeasing, being separated from what is pleasing — are greater than the water in the four great oceans.

"Long have you (repeatedly) experienced the death of a father... the death of a brother... the death of a sister... the death of a son... the death of a daughter... loss with regard to relatives... loss with regard to wealth... loss with regard to disease. The tears you have shed over loss with regard to disease while transmigrating & wandering this long, long time — crying & weeping from being joined with what is displeasing, being separated from what is pleasing — are greater than the water in the four great oceans.

"Why is that? From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries — enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released."
(SN 15.3)

At Savatthi. There the Blessed One said: "From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. A being who has not been your mother at one time in the past is not easy to find... A being who has not been your father... your brother... your sister... your son... your daughter at one time in the past is not easy to find.

"Why is that? From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries — enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released."
(SN 15.14 - 19)

At Savatthi. There the Blessed One said: "From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. When you see someone who has fallen on hard times, overwhelmed with hard times, you should conclude: 'We, too, have experienced just this sort of thing in the course of that long, long time.'

"Why is that? From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries — enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released."
(SN 15.11)

At Savatthi. There the Blessed One said: "From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. When you see someone who is happy & well-provided in life, you should conclude: 'We, too, have experienced just this sort of thing in the course of that long, long time.'

"Why is that? From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries — enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released."
(SN 15.12)

At Savatthi. There the Blessed One said: "From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Just as a stick thrown up in the air lands sometimes on its base, sometimes on its side, sometimes on its tip; in the same way, beings hindered by ignorance and fettered by craving, transmigrating & wandering on, sometimes go from this world to another world, sometimes come from another world to this.

"Why is that? From an inconstruable beginning comes transmigration. A beginning point is not evident, though beings hindered by ignorance and fettered by craving are transmigrating & wandering on. Long have you thus experienced stress, experienced pain, experienced loss, swelling the cemeteries — enough to become disenchanted with all fabricated things, enough to become dispassionate, enough to be released."
(SN 15.9)

The source for the above material:
SN 15.3, 15.9, 15.11, 15.12, 15.14 -19 Copyright © 1997 Thanissaro Bhikkhu. Access to Insight edition © 1997 For free distribution. This work may be republished, reformatted, reprinted, and redistributed in any medium. It is the author's wish, however, that any such republication and redistribution be made available to the public on a free and unrestricted basis and that translations and other derivative works be clearly marked as such.