郑庄公派出两位使臣，分别携带着礼物和信件，前往齐僖公和鲁桓公的国度进行聘问。其中一位使臣顺利完成了任务并回来了，而另一位使臣却将礼物和信件原封不动地带回了郑国。面对这一情况，郑庄公询问原因，那个使臣解释说：“我一到鲁国，就得知了鲁侯被人刺杀的消息，所以我认为主君的信应该是写给前任鲁侯的，因此不能交给新君。” Zheng Zhuanggong seemed puzzled, asking, "How could the Duke of Lu be so cruel as to kill someone?" The messenger replied, "I have inquired thoroughly." He then recounted how the Duke of Lu had been killed by one of his own officials.
According to historical records, the Duke of Lu's father was Duke Hui. His wife passed away early on and he promoted a concubine to become his main wife and gave birth to a son named Prince Qi. However, another concubine also bore him a son called Prince Qi too. Although Prince Qi was older in age but held lower status than Prince Qi's younger brother who was born from the main wife.
The messenger explained that according to custom, the throne should pass down from Father Hui to Prince Qi but instead it went directly to Duke Hui's younger brother because he was deemed unfit for kingship at such an old age.
Prince Qi grew up with resentment towards his uncle who did not give him power as promised after eleven years in power. This time around when he returned from victorious campaigns against Song and even won battles in Chu; he asked for more authority only for his uncle told him that it would be better if they waited until King Wu ascended the throne before making such requests.
Feeling anxious about this situation; Prince Qi decided that it would be better if he could find ways without involving others or else risk being seen as disloyal by those close around him:
"Even though my Uncle said I'll get authority once King Wu takes over," thought prince qi,
"I don't want anyone thinking ill of me! My Uncle is just trying hard enough not wanting me
to have what belongs rightfully mine."
So while planning out how best do things go forward without causing suspicion,
He came upon an idea: One day during winter when everyone stays inside
They all head out into town where there are no guards present nor any signs
Of danger lurking nearby - nothing seems off except perhaps some slight unease
In their hearts knowing something might happen soon enough yet still unaware
