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 & courtesies, he sat 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 & 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 Belatthaputta, 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 & newly gone-forth?"
"There are these four things, great king, that shouldn't be despised & disparaged for being young. Which four? A noble warrior, great king, shouldn't be despised & disparaged for being young. A snake... A fire... And a monk shouldn't be despised & disparaged for being young. These are the four things that shouldn't be despised & disparaged for being young."
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 blaze that feeds on many things, a flame with its blackened trail: A person shouldn't disparage it.
When this was said, King Pasenadi Kosala said to the Blessed One: "Magnificent, lord! 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."
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.