Definition
This idiom indicates that a particular person's statements or instructions must be obeyed without question.
说一不二
In our family, what Mom says, goes; her word is law.
在我们家，妈妈说了算；她的话就是法律。
On this project, what the boss says, goes, and we all have to do as he says.
在这个项目上，老板说了算，我们都必须照他说的做。
In the military, what the commanding officer says, goes; subordinates must obey without question.
在军队中，指挥官说了算；下属必须无条件服从。