A more thorough explanation:

Definition: The letter of the law refers to the exact wording and literal interpretation of a law, rather than considering the intention or purpose behind it. It is also known as litera legis.

Example: A common example of the letter of the law is a speed limit sign that says "50 mph." If a driver goes even one mile per hour over that limit, they are breaking the law, regardless of whether or not it is safe to do so.

Explanation: This example illustrates how the letter of the law can be strict and inflexible, even if it may not always be practical or reasonable. The law is clear and specific, and any deviation from it is considered a violation.