The Jataka, Vol. II, tr. by W.H.D. Rouse, , at sacred-texts.com
"Three forts," etc.--This story the Master told at Jetavana about a brahmin named Kāmanīta. The circumstances will be explained in the Twelfth Book, and the Kāma-Jātaka 1.
[The king of Benares had two sons.] And of these two sons the elder went to Benares, and became king: the youngest was the viceroy. He that was king was given over to the desire of riches, and the lust of the flesh, and greedy of gain.
At the time, the Bodhisatta was Sakka, king of the gods. And as he looked out upon India, and observed that the king of it was given over to these lusts, he said to himself, "I will chastise that king, and make him ashamed." So taking the semblance of a young brahmin, he went to the king and looked at him.
"Whit wants this young fellow?" the king asked.
Said he, "Great king, I see three towns, prosperous, fertile, having elephants, horses, chariots and infantry in plenty, full of ornaments of gold and fine gold. These may be taken with a very small army. I have come hither to offer to get them for you!"
"When shall we go, young man?" asked the king.
"Then leave me now; to-morrow early shall you go."
"Good, my king: hasten to prepare the army!" And so saying  Sakka went back again to his own place.
Next day the king caused the drum to beat, and an army to be made ready; and having summoned his courtiers, he thus bespoke them:--
"Yesterday a young brahmin came and said that he would conquer for me three cities--Uttarapañcāla, Indapatta, and Kekaka. Wherefore now we will go along with that man and conquer those cities. Summon him in all haste!"
"What place did you assign him, my lord, to dwell in?"
"I gave him no place to dwell in," said the king.
"But you gave him wherewith to pay for a lodging!"
"Nay, not even that."
"Then how shall we find him?"
"Seek him in the streets of the city," said the king.
They sought, but found him not. So they came before the king, and told him, "O king, we cannot see him."
Great sorrow fell upon the king. "What glory has been snatched from me!" he groaned; his heart became hot, his blood became disordered, dysentery attacked him, the physicians could not cure him.
After the space of three or four days, Sakka meditated, and was ware of his illness. Said he, "I will cure him: "and in the semblance of a brahmin he went and stood at his door. He caused it to he told the king, "A brahmin physician is come to cure you."
On hearing it, the king answered, "All the great physicians of the court have not been able to cure me. Give him a fee, and let him go." Sakka listened, and made reply: "I want not even money for my lodging, nor will I take fee for my leechcraft. I will cure him: let the king see me!"
"Then let him come in," said the king, on receiving this message. Then Sakka went in, and wishing victory to the king, sat on one side. "Are you going to cure me?" the king asked.
He replied, "Even so, my lord."
"Cure me, then!" said the king.
"Very good, Sire. Tell me the symptoms of your disease, and how it came about,--what you have eaten or drunken, to bring it on, or what you have heard or seen."
"Dear friend, my disease was brought upon me by something that I heard."
Then the other asked, "What was it?" 
"Dear Sir, there came a young brahmin who offered to win and give me power over three cities: and I gave him neither lodging, nor wherewithal to pay for one. He must have grown angry with me, and gone away to some other king. So when I bethought me how great glory had been snatched away from me, this disease came upon me; cure, if you can, this which has come upon me foci my covetousness." And to make the matter clear he uttered the first stanza:--
Then Sakka said, "O king, by simples made with roots you cannot
be cured, but you must be cured with the simple of knowledge:" and he uttered the second verse as follows: 
So spake the great Being to explain his meaning, and he added this yet beyond: "O king, what if you were to get those three cities, then while you reigned over these four cities, could you wear four pairs of robes at once, eat out of four golden dishes, lie on four state beds? O king, one ought not to be mastered by desire. Desire is the root of all evil; when desire is increased, he that cherishes her is cast into the eight great hells, and the sixteen lowest hells, and into all kinds and manner of misery." So the great Being terrified the king with fear of hell and misery, and discoursed to him. And the king, by heating his discourse, got rid of his heartbreak, and in a moment he became whole of his disease.  And Sakka after giving him instruction, and establishing him in virtue, went away to the world of gods. And the king thenceforward gave alms and did good, and he passed away to fare according to his deserts.
When this discourse was ended, the Master identified the Birth:--"The Brother who is a slave to his desires was at that time the king; and I myself was Sakka."
149:1 No. 467.
150:1 The names of Pañcāla, Kuru, and Kekaka are given.