liǎo rú zhǐ zhǎng
了如指掌 (liǎo rú zhǐ zhǎng) is a Chinese word meaning “to know sth like the back of one's hand (idiom); to know (a person, a place etc) inside out”.
Meanings
- 1to know sth like the back of one's hand (idiom)
- 2to know (a person, a place etc) inside out