After Emperor Liu Bang of the Han Dynasty pacified the realm, he prepared to reward his subordinates according to their merits.
Many generals argued endlessly. One said, "I have galloped across battlefields for years, covered in scars—my merit is greatest." Another retorted, "What are you? My merit is far greater!" ...
The ministers argued fiercely, each insisting their own contributions were greater than the others', and that they alone deserved high office and generous rewards—none willing to yield.
After careful deliberation, Liu Bang concluded that Xiao He's contributions were the greatest, so he enfeoffed him as the Marquis of Zan and granted him a vast territory.
At this, the ministers erupted in outrage, deeply unconvinced. Someone said to Liu Bang, "We have fought a hundred battles, risking life and death for you with outstanding achievements, yet now our rewards are less than Xiao He's."
Others said, "Xiao He only plays with words and makes empty arguments. He has never sweated in battle, so why is his merit ranked above ours?"
Emperor Liu Bang declared that Xiao He's strategic brilliance was unmatched and essential for governing the empire. He repeatedly explained to his ministers, "Xiao He's wisdom surpasses yours," until they reluctantly accepted his judgment.
Later, people used "sweating horse merits" to describe the hardships of battle, and now it also refers to contributions made in work.
Source: *Book of Han*, "Annals of Emperor Gao"
Meaning of the Idiom: Later, the Chinese idiom "汗马功劳" came to describe the hardships of battle, and now it also refers to contributions made in work.