Legend has it that the celestial deity who manages horses in heaven is named Bo Le. On earth, people also refer to those exceptionally skilled at discerning the quality of horses as "Bo Le."
The first person to be called Bo Le was originally named Sun Yang, a man from the Spring and Autumn period. Because of his outstanding expertise in the study of horses, people gradually forgot his real name and simply called him Bo Le, a name that has continued to this day.
Once, Bo Le was commissioned by the King of Chu to purchase a fine steed capable of traveling a thousand li in a single day. Bo Le explained to the king that such thousand-li horses were rare and difficult to find, requiring extensive travel and investigation across many regions. He asked the king not to worry and assured him he would do his utmost to fulfill the task.
Bo Le traveled through several states, carefully searching even the Yan and Zhao regions, famous for producing fine horses. Despite his arduous efforts, he still could not find a suitable horse. One day, while returning from the State of Qi, he saw a horse laboriously pulling a salt-laden cart up a steep slope. The horse was panting heavily, and every step seemed agonizingly difficult. Bo Le, who had always felt a close affinity with horses, instinctively walked toward it. As Bo Le approached, the horse suddenly raised its head, widened its eyes, and let out a loud, resonant neigh, as if trying to confide something to Bo Le. Instantly, Bo Le recognized from the sound that this was an exceptionally rare and valuable horse. He said to the cart driver, "On the battlefield, no horse could match this one in speed and strength, but for pulling carts, it's less suited than an ordinary horse. You should sell it to me."
The driver thought Bo Le was a fool. In his eyes, the horse was utterly ordinary—weak, a heavy eater, and emaciated. Without hesitation, he agreed to the sale. Bo Le led the thousand-li horse straight to the State of Chu. When he arrived at the king's palace, Bo Le patted the horse's neck and said, "I've found you a worthy master." As if understanding Bo Le's words, the horse lifted its front hooves, making the ground tremble with a rhythmic thud, stretched its neck, and let out a long, powerful neigh—clear and resonant like a great bell or stone chime, soaring into the sky. Hearing the neigh, the King of Chu came out of the palace. Bo Le pointed at the horse and said, "Your Majesty, I have brought you the thousand-li horse. Please examine it carefully."
The king looked at the horse Bo Le was leading—so thin and wretched in appearance—and believed Bo Le was mocking him. He became somewhat displeased and said, "I trusted your skill in judging horses, which is why I sent you to buy one. But what kind of horse have you bought? This animal can barely walk. How could it possibly go to war?"
Bo Le replied, "This is indeed a true thousand-li horse. However, it has been used to pull carts for a while and was not well fed, which is why it appears so thin. With careful feeding and care, within half a month, it will surely regain its strength."
The king listened, still somewhat skeptical, but ordered his stable hands to care for the horse diligently. Sure enough, the horse soon became strong, vigorous, and magnificent. When the king mounted it and cracked the whip, he felt the wind rushing past his ears, and before he could catch his breath, the horse had galloped over a hundred li. Later, this thousand-li horse galloped across battlefields for the King of Chu, winning him numerous victories. From then on, the king held Bo Le in even higher esteem.