Channa was the attendant who accompanied Prince Siddhattha when he renounced the world and left the palace on horseback.

When the prince attained Buddha hood, Channa also became a bhikkhu.
As a bhikkhu, he was very arrogant and overbearing because of his close connection to the Buddha.

Channa used to say, “I came along with my Master when he left the palace for the forest. At that time, I was the only companion of my Master and there was no one else. But now, Sariputta and Moggallana are saying, ‘we are the Chief Disciples,’ and are strutting about the place.”

When the Buddha sent for him and admonished him for his behavior, he kept silent but continued to abuse and taunt the two Chief Disciples.

Thus the Buddha sent for him and admonished him three times; still, he did not change.

And again, the Buddha sent for Channa and said, “Channa, these two noble bhikkhus are good friends to you; you should associate with them and be on good terms with them.”

Then the Buddha spoke in verse as follows:

“One should not associate with bad friends, nor with the vile.
One should associate with good friends, and with those who are noble.”

[In spite of repeated admonitions and advice given by the Buddha, Channa did as he pleased and continued to scold and abuse the bhikkhus.

The Buddha, knowing this, said that Channa would not change during the Buddha’s lifetime but after his demise (parinibbana) Channa would surely change.

On the eve of his parinibbana, the Buddha called Thera Ananda to his bedside and instructed him to impose the Brahma-punishment (Brahmadanda) to Channa; i.e., for the bhikkhus to simply ignore him and to have nothing to do with him.

After the parinibbana of the Buddha, Channa, learning about the punishment from Thera Ananda, felt a deep and bitter remorse for having done wrong and he fainted three times.

Then, he owned up his guilt to the bhikkhus and asked for pardon.

From that moment, he changed his ways and outlook. He also obeyed their instructions in his meditation practice and soon attained arahatship.]

(The Dhammapada
78,Verses and Stories
Translated by
Daw Mya Tin,M.A.)