笑里藏刀

xiào lǐ cáng dāo

a dagger behind a smile

Character by character

笑xiào
smile

里lǐ
inside

藏cáng
hide

刀dāo
knife

他这个人笑里藏刀，你千万别信他。

He smiles while plotting against you — don’t trust him.

Tone: negative (criticism).

Said of the Tang official Li Yifu, all smiles outside and vicious within; 藏 is cáng.

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