cast the first stone—be the first to bring an accusation against a person:
- Let those of the respectable press who are without sin, cast the first stone.
lay the first stone—lay the foundation of smth.:
- It was Hughes who laid, in 1877, the first stone of radiographic practice by his detailed experiments.
Note: The expression is not equivalent in meaning to the phrase make the first step—perform the first move in a course of action towards attaining a goal:
- Come, let us make the first step towards our wealth.