Samyutta Nikaya XV.12
Sukhita Sutta
Happy
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."