The Jataka, Vol. III, tr. by H.T. Francis and R.A. Neil, , at sacred-texts.com
"With sense so nice," etc.—This story was told by the Master while living in the Bamboo Grove, of prince Ajātasattu. At the time of his conception there arose in his mother, the daughter of the king of Kosala, a chronic longing to drink blood from the right knee of king Bimbisāra 1 (her husband). Being questioned by her attendant ladies, she told them how it was with her. The king too hearing of it called his astrologers and said, "The queen is possessed of such and such a longing. What will be the issue of it?" The astrologers said, "The child conceived in the womb of the queen will kill you and seize your kingdom." "If my son," said the king, "should kill me and seize my kingdom, what is the harm of it?" And then he had his right knee opened with a sword and letting the blood fall into a golden dish gave it to the queen to drink. She thought, "If the son that is born of me should kill his father, what care I for him? " and endeavoured to bring about a miscarriage.  The king hearing of it called her to him and said, "My dear, it is said, my son will slay me and seize my kingdom.
[paragraph continues] But I am not exempt from old age and death: suffer me to behold the face of my child. Henceforth act not after this manner." But she still went to the garden and acted as before. The king on hearing of it forbade her visits to the garden, and when she had gone her full time she gave birth to a son. On his naming-day, because he had been his father's enemy, while still unborn, they called him prince Ajātasattu. As he grew up with his princely surroundings, one day the Master accompanied by five hundred Brethren came to the king's palace and sat down. The assembly of the Brethren with Buddha at their head was entertained by the king with choice food, both hard and soft. And after saluting the Master the king sat down to listen to the law. At this moment they dressed up the young prince and brought him to the king. The king welcomed the child with a strong show of affection and placed him on his lap, and fondling the boy with the natural love of a father for his child, he did not listen to the law. The Master observing his inattention said, "Great king, formerly kings when suspicious of their sons had them kept in a secret place, and gave orders that at their death they were to be brought forth and set upon the throne." And at the request of the king he told him a legend of the olden time.
Once upon a time when Brahmadatta reigned in Benares, the Bodhisatta was a far-famed teacher at Takkasilā and trained many young princes and sons of brahmins in the arts. Now the son of the king of Benares, when he was sixteen years old, came to him and after he had acquired the three Vedas and all the liberal arts and was perfect in them, he took leave of his master. The teacher regarding him by his gift of prognostication thought, "There is danger coming to this man through his son. By my magic power I will deliver him from it." And composing four stanzas he gave them to the young prince and spoke as follows: "My son, after you are seated on the throne, when your son is sixteen years old, utter the first stanza while eating your rice; repeat the second stanza at the time of the great levée; the third, as you are ascending to the palace roof, standing at the head of the stairs, and the fourth,  when entering the royal chamber, as you stand on the threshold."
The prince readily assented to this and saluting his teacher went away. And after acting as viceroy, on his father's death he ascended the throne. His son, when he was sixteen years of age, on the king's going forth to take his pleasure in the garden, observing his father's majesty and power was filled with a desire to kill him and seize upon his kingdom, and spoke to his attendants about it. They said, "True, Sir, what is the good of obtaining power, when one is old? You must by some means or other kill the king and possess yourself of his kingdom." The prince said, "I will kill him by putting poison in his food." So he took some poison and sat down to eat his evening meal with his father. The king, when the rice was just served in the bowl, spoke the first stanza:
Rats keen are to discriminate:
They cared not much the husks to touch,
But grain by grain the rice they ate.
"I am discovered," thought the prince, and not daring to administer the poison in the bowl of rice, he rose up and bowing to the king went away. He told the story to his attendants and said, "To-day I am found out. How now shall I kill him?" From this day forth they lay concealed in the garden, and consulting together in whispers said, "There is still one expedient. When it is time to attend the great levée, gird on your sword, and taking your stand amongst the councillors, when you see the king off his guard, you must strike him a blow with your sword and kill him." Thus they arranged it. The prince readily agreed, and at the time of the great levée, he girt on his sword  and moving about from place to place looked out for an opportunity to strike the king. At this moment the king uttered the second stanza:
By me is understood:
The village plot soft whispered in the ear
That too I hear.
Thought the prince, "My father knows that I am his enemy," and ran away and told his attendants. After the lapse of seven or eight days they said, "Prince, your father is ignorant of your feeling towards him. You only fancy this in your own mind. Put him to death." So one day he took his sword and stood at the top of the stairs in the royal closet. The king standing at the head of the staircase spoke the third stanza:
His tender offspring impotent to make.
Thought the prince, "My father wants to seize me," and in his terror he fled away and told his attendants he had been threatened by his father. After the lapse of a fortnight they said, "Prince, if the king knew this, he would not have put up with it so long a time. Your imagination suggests this to you.  Put him to death." So one day he took his sword and entering the royal chamber on the upper floor of the palace he lay down beneath the couch, intending to slay the king, as soon as he came. At the close of the evening meal, the king sent his retinue away, wishing to lie down, and entering the royal chamber, as he stood on the threshold, he uttered the fourth stanza:
Like one-eyed goat in mustard field that strays,
And who thou art that lurkest here below,
This too I know.
Thought the prince, "My father has found me out. Now he will put me to death." And seized with fear he came out from beneath the couch, and throwing down his sword at the king's feet and saying, "Pardon me, my lord," he lay grovelling before him. The king said, "You thought, no
one knows what I am about." And after rebuking him he ordered him to be bound in chains and put into the prison house, and set a guard over him. Then the king meditated on the virtues of the Bodhisatta. And by and bye he died. When they had celebrated his funeral rites, they took the young prince out of prison and set him on the throne.
The Master here ended his lesson and said, "Thus, Sire, kings of old suspected in cases in which suspicion was justified," and related this incident,  but the king gave no heed to his words. The Master thus identified the Birth: "At that time the far-famed teacher at Takkasilā was I myself."
80:1 Compare Tibetan Tales vi. Prince Jīvaka.