斗粟尺布 — “A peck of millet, a foot of cloth”

The idiom "斗粟尺布" (Dòu sù chǐ bù) originates from the Western Han Dynasty. Liu Chang, the sixth son of Emperor Gaozu Liu Bang, lost his mother at a young age. Empress Lü, following Emperor Gaozu's instructions, adopted Liu Chang.

After Ying Bu, the King of Huainan, rebelled and was subsequently defeated and killed, Liu Chang was enfeoffed as the King of Huainan. Liu Chang, relying on his status as an imperial prince, became exceedingly arrogant. After Emperor Wen ascended the throne, he became even more presumptuous, often defying laws and regulations without fear. Emperor Wen, his elder brother, was also very lenient towards him.

Because Liu Chang held an old grudge against Marquis Piyang, Shen Shiqi, he killed him with an iron club. Emperor Wen pardoned him and did not punish him, which only made Liu Chang more arrogant and lawless. He disregarded the imperial decrees, acting as he pleased in Huainan. He indiscriminately killed innocent people, arbitrarily bestowed noble titles, and even adorned his carriages and horses like those of the emperor. Later, he went so far as to send envoys to ally with Minyue in the south and Xiongnu in the north, planning to raise an army and rebel.

When Liu Chang's rebellion plot was exposed, those who assisted him were either executed or arrested, and Liu Chang himself was brought to Chang'an. Emperor Wen spared him the death penalty, stripped him of his princely title, and exiled him to Shu (modern-day Sichuan). During the journey, Liu Chang starved himself to death.

At that time, some people who were unaware of the full truth mistakenly believed that Emperor Wen had forced his own younger brother to die. They composed a folk song that said: "A foot of cloth can still be sewn, a peck of millet can still be ground; yet two brothers cannot tolerate each other." Later generations derived the idiom "斗粟尺布" from this folk song, which is often used to describe discord or conflict between brothers.