If you can't bite, never show your teeth
Do not make threats you cannot carry out.
English
If you can't bite, never show your teeth
Tiếng Việt
Miệng hùm gan sứa.
Không làm được thì đừng đe dọa.
Examples
- He backed down the moment he was challenged — if you can't bite, never show your teeth.
- She warned him not to bluff: if you can't bite, never show your teeth.