I have heard that on one occasion the Blessed One was staying near Savatthi in Jeta's Grove, Anathapindika's monastery. Then King Pasenadi Kosala went to the Blessed One and, on arrival, exchanged courteous greetings with him. After this exchange of friendly greetings and courtesies, he sat down to one side. As he was sitting there he said to the Blessed One: "Now then, does Master Gotama claim, 'I have awakened to the unexcelled right self-awakening'?"
"If, great king, one speaking rightly could say of anyone, 'He has awakened to the unexcelled right self-awakening,' one could rightly say that of me. For I, great king, have awakened to the unexcelled right self-awakening."
"But Master Gotama, those priests and contemplatives each with his group, each with his community, each the teacher of his group, an honored leader, well-regarded by people at large -- i.e., Purana Kassapa, Makkhali Gosala, Ajita Kesakambalin, Pakudha Kaccayana, Sañjaya Belatthitaputta, and the Nigantha Nathaputta: even they, when I asked them whether they claimed to have awakened to the unexcelled right self-awakening, didn't make that claim. So who is Master Gotama to do so when he is still young and newly gone-forth?"
"There are these four things, great king, that shouldn't be despised and disparaged for being young. Which four? A noble warrior, great king, shouldn't be despised and disparaged for being young. A snake... A fire... And a monk shouldn't be despised and disparaged for being young. These are the four things that shouldn't be despised and disparaged for being young."
That is what the Blessed One said. Having said that, the One Well-Gone, the Teacher, said further:
You shouldn't look down on
-- for being young --
a noble warrior of consummate birth,
a high-born prince of great status.
A person shouldn't disparage him.
For it's possible
that this lord of human beings,
this noble warrior,
will gain the throne
and, angered at that disparagement,
come down harshly
with his royal might.
So, guarding your life,
avoid him.
You shouldn't look down on
-- for being young --
a serpent you meet
in village or wilderness:
A person shouldn't disparage it.
As that potent snake slithers along
with vibrant colors,
it may someday burn the fool,
whether woman or man.
So, guarding your life,
avoid it.
You shouldn't look down on
-- for being young --
a blaze that feeds on many things,
a flame with its blackened trail:
A person shouldn't disparage it.
For if it gains sustenance,
becoming a great mass of flame,
it may someday burn the fool,
whether woman or man.
So, guarding your life,
avoid it.
When a fire burns down a forest
-- that flame with its blackened trail --
the shoots there
take birth once more
with the passage of days and nights.
But if a monk,
his virtue consummate,
burns you with his potency,[1]
you won't acquire sons or cattle
nor will your heirs enjoy wealth.
They become barren,
heir-less,
like palm tree stumps.
So a person who's wise,
out of regard for his own good,
should always show due respect
for a serpent,
a fire,
a noble warrior with high status,
and a monk, his virtue consummate.
When this was said, King Pasenadi Kosala said to the Blessed One: "Magnificent, venerable sir! Magnificent! Just as if he were to place upright what was overturned, to reveal what was hidden, to show the way to one who was lost, or to carry a lamp into the dark so that those with eyes could see forms, in the same way has the Blessed One -- through many lines of reasoning -- made the Dhamma clear. I go to the Blessed One for refuge, to the Dhamma, and to the Community of monks. May the Blessed One remember me as a lay follower who has gone to him for refuge, from this day forward, for life."
Note
1. The "potency" of a virtuous monk is his unwillingness to seek redress when he has been treated wrongly. The bad kamma of having mistreated a monk pure in his virtue is what returns to burn the person who did it.