During the Eastern Jin Dynasty, Huan Xuan, the Duke of Nan Commandery, Yin Zhongkan, the Governor of Jingzhou, and the renowned painter Gu Kaizhi were close friends who often drank and amused themselves together.
One day, the three were drinking together again. Gu Kaizhi, being naturally witty, often came up with amusing ideas. He said, "This way of drinking is dull. How about each of us says a dangerous phrase?"
During the Southern Dynasties, a popular game among literati was "dangerous words"—composing a single line of poetry describing something perilous, with the most hazardous verse winning the highest praise.
Huan Xuan was the first to agree, saying, "I'll go first. Washing rice with a spearhead and cooking with a sword tip."
This sentence means: using a spearhead to wash rice and a sharp sword to stir fire will puncture the rice basket and burn the sword red. This is certainly very dangerous.
Yin Zhongkan added, "An old man of a hundred years climbing a withered branch."
A centenarian clinging to a withered branch was clearly far more perilous than what Huan Xuan had described, and Yin Zhongkan could not help but show a smug expression on his face.
Then it was Gu Kaizhi's turn. Gu Kaizhi said confidently, "A baby lies on the well pulley."
A baby lying on a rolling well pulley is even more dangerous—that was the line that won the contest
Sitting beside Yin Zhongkan, a military advisor eagerly joined in, saying, "Let me try one." Yin Zhongkan glanced at him and replied, "Go ahead, let's hear it!" The advisor blurted out, "A blind man rides a blind horse, approaching a deep pool at midnight!" The imagery was far more perilous than the others' verses. But Yin Zhongkan's face instantly darkened as he snapped, "You're going too far!"
Huan Xuan and Gu Kaizhi couldn't help but snicker. It turned out that Yin Zhongkan was blind in one eye, and that adjutant, unaware of the taboo, had touched a nerve. Later, the idiom "a blind man riding a blind horse" came to describe extreme danger, peril upon peril.
Source: *A New Account of the Tales of the World*, "Taunting and Teasing"
Meaning of the Idiom: Later, the Chinese idiom "盲人骑瞎马" came to describe extreme danger, peril upon peril.