挖祖墳

Simplified: 挖祖坟

wāzǔfén ㄨㄚ ㄗㄨˇ ㄈㄣˊ

    • to do something seriously harmful to someone

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
to dig up the ancestral grave
Meaning
To do something seriously harmful to someone, as if desecrating their ancestors' graves. Strongly critical.

Sources