推心置腹 — “To open one's heart to others”

During the late Western Han Dynasty, Wang Mang usurped the throne, plunging the realm into chaos. Farmers rose in rebellion, and various heroes emerged to challenge Wang Mang. In early 23 AD, Liu Xuan was enthroned as emperor, with Liu Xiu serving as a general. Wang Mang repeatedly dispatched troops to attack Liu Xuan. In these battles, Liu Xiu repeatedly distinguished himself, earning the title 'King Xiao' from Liu Xuan.

Meanwhile, Liu Xiu also battled another rebel leader, Wang Lang, for many years in the areas around the Hutuo and Fuyang rivers in what is now central-southern Hebei province, achieving numerous victories. In the autumn of 24 AD, Liu Xiu led his forces to attack a peasant uprising army at Wu (southeast of present-day Shulu County, Hebei), utterly defeating them.

He then conferred titles of Marquis upon the surrendered commanders. However, the surrendered soldiers remained uneasy, uncertain of Liu Xiu's true intentions.

Upon learning of their apprehension, Liu Xiu sought to reassure them. He issued an order for all surrendered troops to return to their original units and command their own soldiers. Liu Xiu himself, with minimal escort, rode through the various units, showing no signs of precaution. This gesture convinced the surrendered men of his sincerity. They often whispered among themselves, saying, 'King Xiao takes his true heart and places it into our breasts; what more do we have to fear? Should we not fight for him and dedicate our efforts?'

The original passage from 'Book of the Later Han' (Hou Han Shu - Records of Emperor Guangwu) states: 'King Xiao places his red heart into people's bellies, how can they not repay him with their lives?' Later generations condensed the phrase '推赤心置人腹中' (to place one's red heart into another's belly) into the idiom '推心置腹', signifying treating others with utmost sincerity.