The Jataka, Vol. II, tr. by W.H.D. Rouse, , at sacred-texts.com
"Rich food and drink," etc.--This story the Master told while he was dwelling at the shrine of Aggālava, near Ālavī, about the rules for building cells.
Some Brethren who lived in Ālavī 2 were begging 3 from all quarters the materials for houses which they were getting made for themselves. They were for ever dinning and dunning; "Give us a man, give us somebody to do servant's work," and so forth. Everybody was annoyed at this begging and solicitation. So much annoyed were they, that at sight of these Brethren they were startled and scared away.
It happened that the reverend father Mahākassapa entered Ālavī, and traversed the place in quest of alms. The people, as soon as they saw the Elder, ran away as before 4. After mealtime, having returned from his rounds, he summoned the brethren, and thus addressed them: "Once Ālavī was a capital place for alms; why is it so poor now?" They told him the reason.
Now the Blessed One was at the time dwelling at the Aggālava shrine. To the Blessed One came the Elder, and told him all about it. The Master convened the Brethren touching this matter.  "I hear," said he, "that you are building houses and worrying everybody for help. Is this true?" They said it was. Then the Master rebuked them, adding these words: "Even in the serpent world, Brethren, full as it is of the seven precious stones, this kind of begging is distasteful to the serpents. How much more to men, from whom it is as hard to get a rupee as it is to skin a flint!" and he told an old-world tale.
Once upon a time, when Brahmadatta reigned in Benares, the Bodhisatta was born as a rich brahmin's son. When he was old enough to run about, his mother gave birth to another wise being. Both the brothers, when they grew up, were so deeply pained at their parents' death, that they became anchorites, and dwelt in leaf-huts which they made them at a bend of the Ganges river. The elder had his lodge by the upper Ganges, and the younger by the lower river.
One day, a Serpent-King (his name was Maṇikaṇṭha, or Jewel-throat) left his dwelling-place, and taking the shape of a man, walked along the river bank until he came to the younger brother's hermitage. He greeted
the owner, and sat down at one side. They conversed pleasantly together; and such friends did they become, that there was no living apart for them. Often and often came Jewel-throat to visit the younger recluse, and sat talking and chatting; and when he left, so much did he love the man, he put off his shape, and encircled the ascetic with snake's folds, and embraced him, with his great hood upon his head; there he lay a little, till his affection was satisfied; then he let go his friend's body, and bidding him farewell, returned to his own place. For fear of him, the hermit grew thin; he became squalid, lost his colour, grew yellower and yellower, and the veins stood out upon his skin.
It happened one day that he paid a visit to his brother. "Why, brother," said he, "what makes you thin? how did you lose your colour? why are you so yellow, and why do your veins stand out like this upon your skin?"
The other told him all about it.
"Come tell me," said the first, "do you like him to come or not?" . "No, I don't."
"Well, what ornament does the Serpent-King wear when he visits you?"
"A precious jewel!"
"Very well. When he comes again, before he has time to sit down, ask him to give you the jewel. Then he will depart without embracing you in his snaky folds. Next day stand at your door, and ask him for it there; and on the third ask him just as he emerges from the river. He will never visit you again."
The younger promised so to do, and returned to his hut. On the morrow, when the Serpent had come, as he stood there the hermit cried, "Give me your beautiful jewel!" The Serpent hurried away without sitting down. On the day following, the hermit stolid at his door, and called out as the Serpent came--"You would not give me your jewel yesterday! now to-day you must!" And the Serpent slipt off without entering the hut. On the third day, the man called out just as the Serpent was emerging from the water--"This is the third day that I have asked you for it: come, give this jewel to me!" And the Serpent, speaking from his place in the water, refused, in the words of these two stanzas:
"Like lads who wait with tempered sword in hand,
You scare me as my jewel you demand,
You ask too much--the gem I will not give,
Nor ever visit you while I shall live!"
 With these words, the King of the Serpents plunged beneath the water, and went to his own place, never to return.
Then the ascetic, not seeing his beautiful Serpent-King again, became thinner and thinner still; he grew more squalid, lost his colour worse than before, and grew more yellow, and the veins rose thicker on his skin!
The elder brother thought he would go and see how his brother was getting on. He paid him a visit, and found him yellower than he had been before.
"Why, how is this? worse than ever!" said he.
His brother replied, "It is because I never see the lovely King of Serpents!"
"This hermit," said the elder, on hearing his answer, "cannot live without his Serpent-King; "and he repeated the third verse:--
Then he counselled his brother not to grieve, and with this consolation, left him and returned to his own hermitage. And after that  the two brothers cultivated the Faculties and the Attainments, and became destined for the heaven of Brahma.
The Master added, "Thus, Brethren, even in the world of serpents, where are the seven precious stones in plenty, begging is disliked by the serpents: how much more by men!" And, after teaching them this lesson, he identified the Birth:--"At that time, Ānanda was the younger brother, but the elder was I myself."
197:1 I think this Jātaka is represented on the Stupa of Bharhut. In pl. XLII. 1 we see a man sitting before a hut, apparently conversing with a great five-headed cobra. The story is also told in the Vinaya Piṭaka, Suttavibhaṅga, VI. 1. 3.
197:2 The introductory story occurs in the Vinaya, Suttavibhaṅga, Saṁghūdisesa, vi. 1. The sin was importunity.
197:3 Reading saṁyācikāya (as in Suttavibhaṅga).
197:4 Reading patipajjīsu.