The Tang official Lou Shide was known for his self-control. The New Book of Tang says that when others offended him, he gave way and showed no anger. When his younger brother left to govern Daizhou, Lou told him to be patient.
The brother said: “If someone spits in my face, I will just wipe it off.” Lou answered: “Not yet. Wiping it off goes against his anger. Let it dry by itself.” The idiom 唾面自干, letting spit dry on one’s face, comes from this exchange.