What safety measure should be taken before starting the masonry saw?

Grounding the saw is a critical safety measure to prevent electric shock and ensure the safe operation of the equipment. This involves connecting the saw to a grounded outlet or ensuring that the saw's grounding mechanism is functioning properly. This step is essential because masonry saws generate significant power, and if any electrical issues occur, grounding helps direct any stray currents safely away from the operator.

While other considerations such as checking the oil level, ensuring the blade is sharp, and reviewing manual updates are important for the effective functioning and maintenance of the saw, they do not directly address the immediate safety risks associated with starting an electrically powered tool. Grounding is a preventative measure that protects the operator from hazardous situations, making it a paramount step before use.