Here is that which I have heard. Once the Buddha was living at Karanda venuvana in Rajagriha. In those times, the venerable Aniruddha walked among men in the country of Magadha. He came to the dwelling of the mother of the demon Priyankara, and there took lodging. Then, the venerable Aniruddha, during the final watch of the night, sat with his body erect, recited the udana, the po-lo-yen-na, the verses spoken by the sthavira who had seen the Truths, the verses said by the bhiksuni, the verses of the siksapada, the verses yi-p'in meou ni and the sutras; he recited all of these in detail. But during this night, Priyankara wept. Then the mother of the demon Priyankara spoke these words in order to quiet her son:

Demon Priyankara, you must not weep now
One must listen to this bhiksu who recites the verses of the Dharmapada.
He who knows the Dharmapada is able to keep the precepts.
He removes himself from the murder of beings; his words are truthful and he does not employ lies.
He is capable of rejecting inequity and of eluding the way of the demons.

When the mother of the demon Priyankara spoke these words, the cries of the demon Priyankara ceased.

Here is that which I have heard. One day, the Buddha, being in the country of Magadha, walked among men. Accompanied by a large crowd, he arrived at the dwelling of the mother of the demon Punarvasu, and there he took lodging. Then, for the monks, the Buddha explained the Law in accordance with the Four Holy Truths, that is to say, the Truth on suffering; the Truth on the origins of suffering; the Truth on the extinction of suffering; and the Truth on the Way of the extinction of suffering. In those times, the children of the mother of the demon Punarvasu were two, Punarvasu and one daughter-demon, Uttara. During the night, these small children wept. Then the mother of the demon Punarvasu spoke these words in order to teach her children, her son and daughter:

You, Punarvasu and Uttara, do not weep.
Let me hear the Law which the Tathagatha explains.
Neither father nor mother can help their children to avoid suffering
It is in hearing the Law which the Tathagatha explains that one obtains deliverance from suffering
In this world, those people who obey their passions are tormented by all sorts of sufferings
The Tathagatha, in explaining the Law, bestows the means of extinguishing birth and death.
At this moment, I wish to hear the Law; you, you must be still.
Then Punarvasu and the demon Uttara,
Fully obedient to the words of their mother, quieted themselves and
listened in silence.
Then they said to their mother, "Good! We too are happy to hear the Law.
This perfect Buddha Bhagavat, in the Cheng clan of Magadha, has
For all the classes of living beings, explained the Law which redeems from suffering.
He has explained suffering and the cause of suffering, the extinction of suffering and the Way of the extinction of suffering.
In following these Four Holy Truths, in the stillness one achieves nirvana
Mother, listen well now to the Law which the Buddha explains.

Then the mother of the demon Punarvasu said these words:
Marvelous! Intelligent children! You know well to comply with my desire.
You Punarvasu, you have praised well the Buddha, Teacher of the Way.
You, Punarvasu, and you, Uttara, my daughter
Thrill to feelings of joy with me; I have seen the Holy Truths.

Then the mother of the demon Punarvasu having said these lines, her demon children rejoiced with her and were quiet.

*Cited in Taisho as: Za ahan jing, T.II, 99. My English translation is based on Noel Peri's version in "Hariti la mere-de-demons", 34-36.

In those times, the venerable Aniruddha, walking behind the Buddha, arrived at the palace of the Mother of Demons of Magadha. Then Aniruddha, rising early, the night still continuing, sat with body erect and recited the lines of the Dharmapada and the verses po-lo-yen-na and those of the bhadanta. Then, in a high voice, he spoke their meaning and recited the sutras. Then the small child, beloved of the Mother of Demons, named Priyankara wept and shed tears. Then the Mother of Demons, in order to quiet her son said to him, "The holy man recites the sutras, do not weep." And she spoke these lines:

Priyankara, cease your cries;
Listen to the verses of the Dharmapada which the holy man recites.
Who ever hears these verses avoids violation of the precepts,
Obtains purity, and becomes capable of observing the prohibitions.
Priyankara, cease your cries.
Listen to the verses of the Dharmapada which the holy man recites.
Who ever hears these verses obtains the avoidance of death.
Priyankara, cease your cries.
Listen to the verses of the Dharmapada which the holy man recites.
Who ever hears these verses obtains true speech
Priyankara, cease your cries.
Listen to the verses of the Dharmapada which the holy man recites.
Who ever hears these verses escapes the malice of demons.
Because of that, you must cease your cries.

Here is what I have heard. One time, the Buddha was in the country of Magadha in the palace of the mother of the yaksa Punarvasu. During this night, the Buddha took lodging in this palace. The son, the yaksa Punarvasu and the daughter, Uttara, wept during the night. Then the mother, comforting her children and wishing to stop their crying, said these lines:

Punarvasu and Uttara
You at this moment must not cry.
The Buddha, hero of the world, is explaining the principles of the Law.
Let me hear it.
Neither father nor mother can prevent suffering
Only the Bhagavat, skillfully explaining the Law
Is able to bestow upon those who hear it everlasting avoidance of all suffering.
All living beings, following the course of passions,
Sink into the ocean of birth and death.
I wish to hear the law and interrupt the course of passions
Punarvasu and Uttara
Because of this, you must keep silent.

Then Punarvasu spoke these lines:
Now, following the command of my mother, I will not utter a cry.
My younger sister Uttara, she also will be silent.
I beg you, hear this sramana explaining the Marvelous Law.
In Magadha, the Buddha, the greatest among men,
For all living beings, in detail,
Explains the Law of the cessation of suffering
Explains that suffering brings forth suffering
Explains the necessary Law which leads out of suffering
Explains the eight Sacred Paths of the Sages,
And how tranquility attains nirvana.
It is good! Hear the sramana explaining the principles of the Marvelous Law.

The mother replied with these lines:
You, oh intelligent being, that which you said complies with my feelings.
You have praised well this being, the master of the world.
In keeping yourself silent, you allow me to see the four Truths.
Uttara, later you will succeed also in seeing the four Truths.

*Cited in Taisho as: Bieyi za ahan jing, T.II, 100. This legend is not particular to the Sanskrit canon. A passage corresponding rather exactly to the one preceding can be found in the Samyutta nikaya pali, Book X, "Yakkha-samyuttu". My translation is based on Noel Peri's version in "Hariti la mere-de-demons", 36-37.