刻骨铭心

Origin and story

Li Bai's letter to the senior official Li at Anzhou supplies an important antecedent: 銘刻心骨, engraving something on the heart and bones. In the letter, Li Bai acknowledges conduct that could give offense, thanks the official for his generous restraint, and expresses anxious remorse. The engraving image conveys gratitude and self-reproach too deep to forget.

The familiar reordered form 刻骨銘心 appears in a Yuan song suite by Liu Shizhong, praising relief that leaves people profoundly grateful. Neither text describes literal carving. Later use extends beyond gratitude to love, sorrow, humiliation, and other experiences that remain exceptionally vivid in memory.