







铁石心肠 is a Chinese idiom (chengyu) meaning “to have a heart of stone”. To be hard-hearted or unfeeling, showing no pity or compassion. Literally, “heart of iron and stone”.
In 604 AD, Emperor Yang of Sui, Yang Guang, ascended the throne after killing his father. He ordered Xue Daoheng, the Sili Daifu (an official in charge of inspections), to conduct an assessment of all officials in the empire.
Xue Daoheng's appraisal of Jing Su, the Sima of Weizhou, was: "His heart is like iron and stone, becoming even firmer with age."
The minister Yuwen Shu hoped Jing Su would protect his relatives and friends who committed evil deeds by relying on his influence. However, Jing Su brought them to justice one by one.