The Jataka, Vol. IV, tr. by W.H.D. Rouse, , at sacred-texts.com
"Seven days," etc.—This story the Master told in Jetavana, about a certain backsliding brother. The occasion will be explained under the Kusa Birth 2. When the Master had enquired whether this report was true, and the man answered that it was true,  he said, "Brother, wise men in days long gone by, before the Buddha had arisen, even men who had entered upon an unorthodox religious life, for more than fifty years, walking in holiness without caring for it, from the scruples of a sensitive nature never told any one that they had backslidden; and why have you, who have embraced such a religion as ours, that leads to salvation, and who stand in presence of a venerable Buddha such as I am, why have you declared your backsliding before the four kinds of disciples? Why do you not preserve your scruples?" Thus saying, he told an old-world tale.
Once upon a time, in the kingdom of Vamsa, reigned in Kosambī 3 a king named Kosambika. At that time there were two brahmins in a certain town, each possessed of eighty crores, and dear friends one of the other; who, having perceived the mischief which lies in lust, and distributed much goods in almsgiving, both forsook the world, and amid the weeping and wailing of many people, departed to Himalaya, and there built them an hermitage. There for fifty years they lived as ascetics, feeding upon the fruits and roots of the forests where they might chance to glean them; but unto ecstasy they were unable to attain.
After these fifty years had passed by, they went on pilgrimage through the country side to get salt and seasoning, and came to the kingdom of Kāsi. In a certain town of this kingdom lived a householder named Maṇḍavya, who had been a lay friend in householder days of the ascetic Dīpāyana. To this Maṇḍavya came our two friends; who when he saw them, enraptured, built them a hut of leaves, and provided them both with the four necessaries of life. Three or four seasons they dwelt there, and then taking leave of him proceeded on pilgrimage to Benares, where they lived in a cemetery grown over with atimuttaka trees. When Dīpāyana had remained there as long as he wished, he returned to his old comrade again; Maṇḍavya the other ascetic still dwelt in the same place. 4
Now it happened that one day a robber had committed robbery in the town, and was returning from the fact with a quantity of spoil. The owners of the house, and the watchmen, aroused, set up a cry of "Thief!" and the thief, pursued by these, escaped through the sewer, and as he ran swiftly by the cemetery dropt his bundle at the door of the ascetic's hut of leaves. When the owners saw this bundle, they cried, "Ah, you rascal!  you are a robber by night, and in the daytime you go about in the disguise of an ascetic!" So, with reviling and blows, they carried him into the presence of the king.
The king made no enquiry, but only said, "Off with him, impale him upon a stake!" To the cemetery they took him, and lifted him up on a stake of acacia wood; but the stake would not pierce the ascetic's body. Next they brought a nimb stake, but this too would not pierce him: then an iron spike, and no more would that pierce his body. The ascetic wondered what past deed of his could have caused this, and surveyed the past; then there arose in him the knowledge of former existences, and by this as he surveyed the past he saw what he had done long ago; and this it was—the piercing of a fly upon a splinter of ebony.
It is said that in a former existence he had been the son of a carpenter. Once he went to the place where his father was wont to hew trees, and with an ebony splinter pierced a fly as if impaling it. And it was just this sin that found him out when he came to that supreme moment. He perceived that here then was no getting free from sin; so to the king's men he said, "If you wish to impale me, take a stake of ebony wood." This they did, and spitted him upon it, and leaving a guard to watch him they went away.
The watchmen from a place of concealment observed all that came to look upon him. Now Dīpāyana, thinking "It is long since I saw my comrade the ascetic," came to find him; and having heard that he had been hanging a whole day impaled by the roadside, he went up to him, and standing on one side, asked what he had done. "Nothing," quoth he. "Can you guard against ill feeling, or not?" asked the other. "Good friend," said he, "neither against those who have seized me, nor against the king, either, is there any ill feeling in my mind."—"If that is so, the shadow of one so virtuous is delightful to me," and with these words down he sat by the side of the stake. Then upon his body from the body of Maṇḍavya fell gouts of gore; and these as they fell upon the golden skin, and there dried, became black spots upon it; which gave him the name of Kaṇha or Black Dīpāyana from thenceforth. And he sat there all the night.
Next day the watchmen went and told the matter to the king. "I
have acted rashly," said the king; and with speed he hastened to the spot,  and asked Dīpāyana what made him sit by the stake. "Great king," answered he, "I sit here to guard him. But say, what has he done, or what left undone, that you treat him thus?" He explained that the matter had not been investigated. The other replied, "Great king, a king ought to act with circumspection; an idle layman who loves pleasure is not good, etc. 1," and with other such admonitions he discoursed to him.
When the king found that Maṇḍavya was innocent, he ordered the stake to be drawn out. But try as they would, out it would not come. Said Maṇḍavya, "Sire, I have received this dire disgrace for a fault done long ago, and it is impossible to draw the stake from my body. But if you wish to spare my life, bring a saw, and cut it off flush with the skin." So the king had this done; and the part of the stake within his body remained there. For on that previous occasion they say that he took a little piece of diamond, and pierced the fly's duct, so that it did not die then, nor until the proper end of its life; and therefore also the man did not die, they say.
The king saluted these ascetics, and craved pardon; and settling them both in his park, he looked after them there. And from that time Maṇḍavya was called Maṇḍavya with the Peg. And he lived in this place near the king; and Dīpāyana, after healing his friend's wound, went back to his friend Maṇḍavya the householder. When they saw him enter the leaf-hut, they told it to his friend. When he heard it, he was delighted; and with wife and child, taking plenty of scents, garlands, oil, and sugar, and so forth, he came to the leaf hut; greeting Dīpāyana, washing and anointing his feet, and giving him to drink, he sat listening to the tale of Maṇḍavya of the Peg. Then his son, a young man named Yañña-datta, was playing with a ball at the end of the covered walk. There a snake lived in an ant-hill. The lad's ball, thrown upon the ground, ran into the hole of the ant-hill and fell upon the snake. Not knowing this, the lad put his hand into the hole. The snake enraged bit the boy's hand; down he fell in a faint because of the strength of the snake's poison.  Thereupon his parents, finding their son snake-bitten, lifted him up and took him to the ascetic; laying him at the ascetic's feet, they said, "Sir, religious people know simples and charms; please cure our son."—"I know no simples; I do not ply the physician's trade."—"You are a man of religion. Have pity then, Sir, upon this lad, and do the Act of Truth." "Good," said the ascetic, "an Act of Truth I will do."And laying hands upon the head of Yañña-datta, he recited the first stanza:—
Pure I lived, desiring merit:
Since then, for fifty years apart,
Self-absorbed, I do declare it,
Here, unwillingly, I live:
May this truth a blessing give:
Poison baulked, the lad revive!"
No sooner done this Act of Truth, out from the chest of Yañña-datta the poison came, and sank into the ground. The lad opened his eyes, and with a look at his parents, cried "Mother!" then turned over, and lay still. Then Black Dīpāyana said to the father, "See, I have used my power; now is the time to use yours." He answered, "So will I do an Act of Truth"; and laying a hand upon his son's breast, he repeated the second stanza:
All chance comers entertaining,
 Yet still the good and wise knew not
I was my true self restraining;
If unwillingly I give,
May this truth a blessing give,
Poison baulked, the lad revive!"
After the doing of this Act of Truth, out from his back came the poison, and sank into the ground. The lad sat up, but could not stand. Then the father said to the mother, "Lady, I have used my power; now it is yours by an Act of Truth to cause your son to arise and walk." Said she, "I too have a Truth to tell, but in your presence I cannot declare it." "Lady," quoth he, "by all and any means make my son whole." She answered, "Very well," and her Act of Truth is given in the third stanza:
In yonder hole, my son,
And this thy father, are, I say,
In my indifference, one:
May this Truth a blessing give:
Poison baulked, the lad revive!"
 No sooner done was this Act of Truth, than all the poison fell and sank into the ground; and Yañña-datta, rising with all his body purged of the poison, began to play. When the son had in this way risen up, Maṇḍavya asked what was in Dīpāyana's mind by the fourth stanza:
Save Kaṇha, all in no unwilling mood;
What makes thee shrink, Dīpāyana, and why
Unwilling walk the path of sanctity?"
To answer this, the other repeated the fifth stanza:
"An idiot, a fool!" so might one think:—
’Tis this that makes me shrink,
Thus walk I holy, though the wish I lack,
The cause why I do well, is this—
1Praised of the wise the good man's dwelling is."
Thus having explained his own thought, he asked Maṇḍavya yet again in the sixth stanza:
Food and drink in store supplying:
Sages, travellers, brahmins here
Thirst and hunger satisfying.
Didst thou fear some scandal, still
Giving, yet against thy will?"
Then Maṇḍavya explained his thoughts by the seventh stanza:
Lords of gifts most free in giving;
And I followed with all care
Our ancestral way of living;
Lest degenerate I should be
I gave gifts unwillingly."
After saying this, Maṇḍavya asked his wife a question in the words of the eighth stanza:
I brought thee from thy home to be my wife,
Thou didst not tell me thy indifference,
How without love thou livedst all thy life.
Then why, O fair-limbed lady, didst thou stay
And live with me in this unloving way?"
And she replied to him by repeating the ninth. stanza:
For wedded wife to take a newer mate,
Nor ever has been; and this custom I
Would keep, lest I be called degenerate.
T’was fear of such report that bade me stay
And live with thee in this unloving way."
 But when this was said, a thought passed through her mind "My secret is told to my husband, the secret never told before! He will be angry with me; I will crave pardon in the presence of this ascetic, our confidant." And to this end she repeated the tenth stanza:
For our son's sake may it be pardoned.
Stronger than parents' love is nothing here;
Our Yañña-datta lives, who was but dead!"
"Arise, lady," said Maṇḍavya, "I forgive you. Henceforth do not be hard to me; I will never grieve you." And the Bodhisatta said, addressing Maṇḍavya, "In gathering ill-gotten gains, and in disbelieving that when you give liberally, the deed is a seed that brings fruit, in this you have done wrong. For the future believe in the merit of gifts, and give them. "This the other promised, and in his turn said to the Bodhisatta, "Sir, you have yourself done wrong in accepting our gifts when walking the path of holiness against your will. Now in order that your deeds may bear abundant fruit, do you for the future walk in holiness with a tranquil heart and pure, full of ecstatic joy." Then they took leave of the Great Being and departed.
From that time forward the wife loved her husband; Maṇḍavya with tranquil heart gave gifts with faith; the Bodhisatta, dispelling his unwillingness, cultivated the ecstatic Faculty, and became destined for Brahma's heaven.
This discourse ended, the Master declared the Truths: (now at the conclusion of the Truths the backslider was established in the fruit of the First Path:) and identified the Birth:—"At that time Ānanda was Maṇḍavya,  Visākhā the wife, Rāhula the son, Sāriputta was Maṇḍavya of the Peg, and I was myself Black Dīpāyana."
17:1 See Grimblot's Sept Suttas Palies. This story, with the first stanza, is briefly given in the Cariyā-Piṭaka, p 99f.
17:2 No. 531.
17:3 On the Ganges.
17:4 In this confusing tale, Maṇḍavya is the name of one of the ascetics and also of the householder, Dīpāyana is the name of the other ascetic.
19:1 See vol. iii., p. 70.
21:1 Or, Praised of the wise and good religion is.
21:2 The word may possibly mean public-house: either is a "drinking place" (avapāna).