Mahathera Ledi Sayadaw - Abhidhamma.com

Nakhasikha Sutta
"At one time the Buddha, showing them some dust which he had taken upon the tip of his fingernail,
addressed the disciples thus: 'If, O Bhikkhus, these few grains of dust upon my finger-nail
and all the dust in the universe were compared in quantity, which would you say was less, and
which more' The disciples replied: 'Lord, the dust on your finger- nail is less, and that of the
universe is more. Surely, Lord, the dust on your finger-nail is not worthy of mention in
comparison with the dust of the universe.' Then the Buddha continued; 'Even so, Bhikkhus, those
who are reborn in the abodes of men and Devas whence they have expired, are very few even as
the few grains of dust on my finger-nail; and those who are reborn in the four realms of misery are
exceedingly many, even as the dust of the great universe. Again, those who have expired from the
four miserable worlds and are reborn in the abodes of men and Devas are few even as the grains
of dust on my finger-nail; and those who are repeatedly reborn in the four miserable worlds are
innumerable, even as the grains of dust of the great universe."
What has just been said is the substance of the Nakhasikha Sutta. But, to say nothing of the beings
of all the four realms of misery, the creatures that inhabit the four great oceans alone will suffice
to make evident how great is the evil of Vinipatana-gati, that is, the dispersion, the variety of
possible kinds of existence after death.
Kanakacchapa-Sutta:
"At one time, the Buddha addressed the disciples thus: 'There is, O Bhikkhus, in the ocean a
turtle, both of whose eyes are blind. He plunges into the water of the unfathomable ocean and
swims about incessantly in any direction wherever his head may lead. There is also in the ocean
the yoke of a cart which is ceaselessly floating about on the surface of the water, and is carried
away in all directions by tide, current and wind. Thus these two go on throughout an incalculable
space of time: perchance it happens that in the course of time the yoke arrives at the precise place
and time where and when the turtle puts up his head, and yokes on to it. Now, O Bhikkhus, is it
possible that such a time might come as is said' 'In ordinary truth, O Lord,' replied the Bhikkhus
'it is impossible; but time being so spacious, and an aeon lasting so long, it may be admitted that
perhaps at some time or other it might be possible for the two to yoke together, as said; if the
blind tortoise lives long enough, and the yoke does not tend to rot and break up before such a
coincidence comes to pass.'
Then the Buddha said, 'O Bhikkhus, the occurence of such a strange thing is not to be counted a
difficult one; for there is still a greater, a harder, a hundred times, a thousand times more difficult
than this lying hidden from your knowledge. And what is this It is, O Bhikkhus, the obtaining of
the opportunity of becoming a man again by a man who has expired and is reborn once in any of
the four realms of misery. The occurrence of the yoking of the blind tortoise is not worth thinking
of as a difficult occurrence in comparison therewith. Because those who perform good deeds and
abstain from doing bad alone can obtain the existence of men and Devas. The beings in the four
miserable worlds cannot discern what is virtuous and what vicious, what good and what bad, what
moral and what immoral, what meritorious and what demeritorious, and consequently they live a
life of immorality and demerit, tormenting one another with all their power. Those creatures of the
Niraya and Peta abode in particular, live a very miserable life on account of punishments and
torments which they experience with sorrow, pain and distress. Therefore, O Bhikkhus, the
opportunity of being reborn in the abode of men is a hundred times, a thousand times harder to
obtain than the encountering of the blind turtle with the yoke."
According to this Sutta, why those creatures who are born in the miserable planes are far from
human existence is because they never look up but always look down. And what is meant by
looking down The ignorance in them by degrees becomes greater and stronger from one