搬磚砸腳 [－砖－脚]

Jyutping bun1 zyun1 zaap3 goek3
Pinyin bān zhuān zá jiǎo

Definitions (CC-CEDICT)
  1. to hurt oneself by one's own doing
  2. to boomerang
  3. to shoot oneself in the foot (idiom)