During the Warring States period, Duke Ling of Qi had a peculiar hobby: he enjoyed seeing women dressed in men's clothing. As a result, from the queen to the palace consorts and maids, all the women in the palace began wearing men's attire. Women across the state soon followed suit, and for a time, women throughout the land were all wearing men's clothes.
As a result, people across the state could not tell men from women, causing much unnecessary trouble. When local officials reported this to Duke Ling of Qi, he agreed it was abnormal. He then issued a decree to all regions:
"From now on, anywhere in the country, any woman found wearing men's clothing shall have her clothes torn and her belt broken upon discovery!"
Duke Ling of Qi initially believed that once the ban was issued, the trend of women wearing men's clothing would be stopped. However, after some time, despite many women having their clothes torn and belts broken, many still wore men's attire, and in major cities like the capital, the practice proved impossible to eradicate.
Duke Ling of Qi was very puzzled and asked his prime minister Yan Ying, "I have already ordered a ban on women wearing men's clothing, so why won't the people follow my command?"
Yan Ying hit the nail on the head, replying, "Your Majesty, you allow women in the palace to wear men's clothing, yet forbid those outside the palace from doing the same—this is like hanging a sheep's head at the shop door but selling dog meat inside. How can anyone be convinced? Only by first changing the fashion within the palace can you hope to transform the customs of the entire kingdom."
Duke Ling of Qi humbly heeded the advice of his minister Yan Ying and immediately ordered all women in the palace to switch back to women's clothing. Within a month, no woman in the entire state wore men's attire anymore.
Later, the idiom "hanging a sheep's head while selling dog meat" came to be used as a metaphor for deceiving people with false fronts and fake goods, where the name does not match the reality.
Source: *Yanzi's Spring and Autumn Annals*, "Inner Miscellaneous Chapters"
Meaning of the Idiom: Later, the Chinese idiom "挂羊头卖狗肉" came to describe how deceiving people with false fronts and fake goods, where the name does not match the reality.