Rainbows are arched, and a white rainbow piercing through the sun would be an exceptionally long one. Rainbows contain seven colors, but a white rainbow is actually a rare solar halo phenomenon. The ancients considered it an ominous sign from heaven warning the people. The *Strategies of the Warring States*, "Strategies of Wei," records: "When Nie Zheng assassinated Han Gui, a white rainbow pierced the sun."
During the Warring States period, Yan Sui, a minister of the state of Han, publicly accused the prime minister Han Gui of political missteps in court, and the two erupted into a heated argument that escalated to the point of drawing swords against each other.
Han Gui was a petty man who would avenge the slightest grievance. Yan Sui, fearing retaliation, fled to the state of Qi, but his heart burned with resentment, and he sought someone to eliminate Han Gui. Hearing that the warrior Nie Zheng, who had killed a man and was hiding from vengeance, now worked as a butcher in the marketplace, Yan Sui brought wine and food to visit him.
Soon after, as the two grew acquainted, Nie Zheng's mother emerged from the back hall to greet the guest. Yan Sui immediately presented her with a hundred yi of gold as a gift.
Nie Zheng refused, saying, "I live in hiding with my elderly mother and sister in Qi, working as a dog butcher—a humble trade, but enough to get by. I'm just a commoner, unworthy of such a generous gift from a gentleman." Yan Sui replied, "To be honest, I too am a fugitive. I admire your integrity and loyalty. This small gift of a hundred gold pieces is merely a birthday offering for your mother—nothing more." Nie Zheng answered, "I'm not a coward, but I fear implicating my mother. As long as she lives, I will not involve myself in worldly affairs."
After repeated refusals, Nie Zheng ultimately declined the gift money.
After a time, Nie's mother passed away. After Nie Zheng completed his mourning period, he sighed deeply and said, "I am but a poor butcher, yet Yan Zhongzi, a man of high rank, honored me with wine, food, and gold. I did not repay him before because I had to care for my mother. Now that my mother has lived out her natural years, I will devote myself to my benefactor."
Without waiting for a servant to announce him, Yan Sui was already standing at the gate, greeting his guest.
Yan Sui said, "My enemy is the Han prime minister Han Gui, whose clan is large and whose residence is heavily guarded. I have already prepared sturdy chariots, swift horses, and brave warriors to accompany you in accomplishing this great deed."
Nie Zheng said, "Assassinating a feudal lord's prime minister is useless no matter how many warriors you have. Besides, with more people, someone is bound to be captured alive during the operation, and under interrogation they will reveal the instigator. In that case, the state of Han will never let you off. Many people won't do—I'll go alone."
Nie Zheng, armed with his sword, traveled alone to the Han capital of Yangzhai. Seizing the moment when the Han prime minister was receiving guests, he burst through layers of guards, took everyone by surprise, and charged up the hall steps. With a single stroke, he assassinated Han Gui. Before the guards could even reach him, Nie Zheng slashed his own face, gouged out his eyes, and then disemboweled himself, ending his life.
In the state of Han, the assassins were left exposed in the streets, with a reward of a thousand gold pieces offered to anyone who would identify the bodies. Nie Zheng's sister, Nie Ying, wept bitterly over her brother's corpse and cried out, "My brother disfigured himself and took his own life to protect Yan Zhongzi and me—his loyalty and righteousness reach the heavens. How could I let his heroic name be forgotten out of fear for my own safety? I am Nie Ying, sister of the deceased Nie Zheng!" She wailed three times, overcome with grief, and died beside her brother's body.
Later, the idiom "white rainbow piercing the sun" came to symbolize an omen of disaster.
Source: *Strategies of the Warring States*, Chapter "Strategies of Wei"
Meaning of the Idiom: Later, the Chinese idiom "白虹贯日" came to describe an omen of disaster.