During the Warring States period, Queen Zhao Wei of Zhao, wife of King Zhao Huiwen, was known as an enlightened and capable ruler who helped her husband govern the state, earning considerable prestige among the feudal lords.
Once, King Xiang of Qi sent an envoy with a state letter to visit Queen Wei of Zhao. Queen Wei took the letter without even glancing at it and asked the Qi envoy, "How is your kingdom's harvest this year—no disasters, I hope? Are the people free from major illness or calamity? And is your king in good health?"
The Qi envoy, displeased, retorted, "Your Majesty, I have been sent by the King of Qi specifically to convey his regards. By protocol, you should first inquire after the king's well-being. Yet you ask about the harvest and the people's livelihood before asking about our sovereign—are you not elevating the lowly while demeaning the noble?"
Queen Zhao Wei listened and smiled, saying, "What you said is not right. Please think: without a good harvest, could the people survive? And where would the people be? Without the people, where would the ruler be?"
Then, Queen Zhao Wei continued meaningfully, "Thus, when asking, one should not abandon the root to inquire about the branches!" This meant that on this matter, following past customs would precisely discard the essential and ask about the trivial—an unreasonable approach.
"Neglecting the root for the branch" — also written as "seeking the branch while abandoning the root" — is an idiom derived from this story. It is now often used to describe focusing on trivial, secondary matters instead of the fundamental, essential ones when thinking or acting.
Source: *Strategies of the Warring States*, Chapter "Strategies of Qi"
Meaning of the Idiom: Later, the Chinese idiom "舍本逐末" came to describe focusing on trivial, secondary matters instead of the fundamental, essential ones when thinking or acting.