During the Spring and Autumn period, Duke Xian of Jin, in his old age, doted on his concubine Li Ji. Li Ji was determined to make her own son Xi Qi the crown prince, but the duke already had eight sons, including Shen Sheng, who had long been named heir, as well as Chong'er and Yi Wu. So Li Ji plotted to have Shen Sheng killed, then falsely accused Yi Wu and Chong'er of conspiring with him, forcing both princes to flee into exile.
In 651 BCE, Duke Xian of Jin fell gravely ill and, on his deathbed, entrusted his young son Xiqi to the care of his trusted minister Xun Xi. Thus, at just fifteen years old, Xiqi ascended the throne of the state of Jin.
Two other ministers, Li Ke and Pi Zheng, had long resented Li Ji's schemes and planned to install the virtuous Chong'er as ruler, but Xun Xi disagreed. Li Ke and Pi Zheng then sent men disguised into the palace to assassinate Xi Qi. Li Ji placed her three-year-old nephew Zhuozi on the throne instead. Refusing to stop, Li Ke and Pi Zheng led soldiers into the court, killing Zhuozi and Xun Xi, then dragged Li Ji to the marketplace and beat her to death.
After eliminating Li Ji and her son, Li Ke sent messengers to welcome Chong'er back to the state to take the throne, but Chong'er declined. Other officials then proposed bringing Yiwu back to rule. Though Li Ke knew Yiwu was greedy and ruthless, with no other choice since Chong'er refused, he reluctantly agreed.
When Yiwu received the news, he was overjoyed, but his advisor Xi Rui warned, 'Returning to Jin will require Qin's support.' So Yiwu sent Xi Rui to offer Qin five cities in exchange for military aid, and he also sent a letter to Li Ke, promising him land once he ascended the throne.
After taking the throne, Yiwu reneged on his promise to grant Li Ke the fiefdom and stripped him of power. Realizing Yiwu was truly ruthless and ungrateful, Li Ke was filled with deep regret.
But Yiwu did not let the matter rest. Fearing that Li Ke might later collude with Chong'er to rebel, he decided to kill him. He sent Xi Rui to Li Ke's home with a message: "Without you, I could not have become ruler. But you have killed two rulers and one high minister—does that not make it too difficult to be your ruler?"
Li Ke understood immediately—he was being ordered to take his own life
The meaning is: If we don't depose them, how can the ruler become king? If you want to frame someone, are you afraid of lacking an excuse?
With that, Li Ke drew his sword and took his own life.
Later, people used the idiom "If you want to accuse someone, you will never lack a pretext" to refer to arbitrarily framing others.
Source: *Zuo Zhuan*, Chapter "The Tenth Year of Duke Xi"
Meaning of the Idiom: Later, the Chinese idiom "欲加之罪，何患无辞" came to describe If you want to accuse someone, you will never lack a pretext.