rú lǚ bó bīng

如履薄冰

walking on thin ice

walking on egg shells; act with extreme caution

Example:

《诗》云：“战战兢兢, 如临深渊, 如履薄冰。”(《论语》)
《Shī》yún：“zhànzhànjīngjīng, rúlínshēnyuān, rúlǚbáobīng. ”(《Lúnyǔ》)
The Songs says: “In fear and trembling, | As if approaching a deep abyss, | As if walking on thin ice.”