“Mendicants, in some past lives the Realized One was reborn as a human being. He refrained from harsh speech. He spoke in a way that’s mellow, pleasing to the ear, lovely, going to the heart, polite, likable and agreeable to the people. Due to performing those deeds he was reborn in a heavenly realm. When he came back to this state of existence he obtained these two marks: he has a large tongue, and the voice of Brahmā, like a cuckoo’s call.

Possessing these marks, if he stays at home he becomes a wheel-turning monarch. And what does he obtain as king? He has a persuasive voice. His words are persuasive to brahmins and householders, people of town and country, treasury officials, military officers, guardsmen, ministers, counselors, rulers, tax beneficiaries, and princes. That’s what he obtains as king. And what does he obtain as Buddha? He has a persuasive voice. His words are persuasive to monks, nuns, laymen, laywomen, gods, humans, demons, dragons, and fairies. That’s what he obtains as Buddha.” That is what the Buddha said.

On this it is said:

“He never spoke a loud harsh word,
insulting, quarrelsome,
causing harm, rude, crushing the people.
His speech was sweet, helpful, and kind.

He uttered words dear to the mind,
going to the heart, pleasing to the ear.
He enjoyed the fruit of his good verbal conduct,
experiencing the fruit of good deeds in heaven.

Having experienced that fruit,
on his return to here he acquired the voice of Brahmā.
His tongue was long and wide,
and his speech was persuasive.

Even as householder his speech brings prosperity.
But if that man goes forth,
speaking often to the people,
they’ll be persuaded by his fair words.”