This is as I heard. At one time the Buddha was living in the city of Rājagaha, in the Bamboo Garden, in the squirrels’ feeding ground.
Asundarika of the brahmin caste heard a rumour that a man from his clan had become a monk under the Buddha. Asundarika was not happy about this. He got angry and went to the Buddha. He was yelling and insulting the Buddha with rude, harsh words.
But when he said this, the Buddha kept silent.
Then Asundarika said to the Buddha, “Hey monk, do you think you have won this battle?”
“The fool thinks he has won,
when speaking with harsh words.
However, patience is the true victory,
for those who praise patience.
“When you get angry at an angry person,
you just make things worse for yourself.
When you don’t get angry at an angry person,
you win a battle hard to win.
“When you know that the other person is angry,
if you’re patient, mindful and calm,
then you act for the good of both
for yourself and the other person.
“People unfamiliar with the Buddha’s teachings
consider that the person who acts
for the good of both oneself and the other
to be a fool.”
When the Buddha taught this Dhamma, Asundarika said to the Buddha, “Excellent, Master Gotama! Excellent! Just as if someone turned upright, what was upside down, revealed what was hidden, pointed out the path to whoever was lost, or lit a lamp in the dark so people with good eyes could see what’s there, Master Gotama taught me the Dhamma, which is clear in many ways. I go for refuge to Master Gotama, to the Dhamma, and to the Saṅgha. Bhante, may I become a monk under you?”
And he became a monk under the Buddha. Not long after his ordination, Bhante Asundarika, living alone, withdrawn, diligent, passionate, and firm, soon realized the supreme goal of the spiritual path in this very life. He achieved with his own wisdom the goal for which a son would leave the lay life to become a monk.
He realized: “Rebirth has ended. The spiritual journey has been completed. What had to be done to end suffering has been done. There will be no rebirth.” Therefore, Bhante Asundarika became one of the enlightened monks.