I would like to share this story from the book Seven Great Religions
by Annie Besant.

http://www.questbooks.net/title.cfm?bookid=55

[One day Buddha's] ... Bhikkhus were quarrelling
violently ... and hatred ruled where peace
ought to have been. Then the Buddha called them to
him, and he told them a story. It was the story of a
king of Kasi who made war against the king of
Kosala, and drove him away from his kingdom and
took it to himself. The dispossessed king and his
wife went and lived in a poor hovel, and there a son
was born to them. One who had been his barber
seeking to curry the favor with the conqueror,
betrayed him and the king sent forth and seized the
fugitive and his wife and gave them over to the
executioner. The son, who had been sent away for
safety, returned and saw -- his father and mother on
their way to their death and he pressed through the
crowd. The father whispered: 'My son, be not long,
be not short; hatred ceases not by hatred; by
non-hatred it ceases.' The son pondered over the
father's words but he did not understand them.

Presently he took service under the king who had
slain his mother and father, after reducing them to
beggary, and, attracting his king's attention, was
taken as his personal attendant. The king loved the
youth, and used to sleep with his head in his lap. As
he slept there one day the young prince thought,
'This king is in my power; he has slain my father
and mother; he has reduced me to misery; he is
helpless, I will slay him;' and he drew out his sword.
But his father's words came to his mind: 'Be not
short,' and he knew it meant: 'Be not hasty in your
action;' he put the sword back and remembered the
other words, that hatred ceases not by hatred.

The king awoke and said he dreamt that the
prince he had dispossessed had slain him, and the
youth, drawing his sword, revealed himself and told
him that his life was at his mercy. The king prayed
for his life, and the prince answered him: 'Nay, 0
King, I have forfeited my life by this threat, and thou
must give me back my life and thy pardon.' So he
spared the king's life, and the king pardoned the
offence. Then the prince told him of his father's
dying words: 'My father taught me that I must not be
long -- I must not keep hatred; I must not be short
-- I must not be hasty in action. That hatred ceases
not by hatred at any time, but hatred ceases by love.
For if I had slain thee, thy friends would have slain
me in return, and my friends would then have slain
thy friends, and so hatred would not have ceased;
but now we have each given to the other his life, and
thus hatred ceased by love.' The disciples became
reconciled with each other among themselves, and
peace was restored within the Order.