A well-known phrase or saying is often the easiest way to express a sentiment that might otherwise cause offense. It’s a way of driving home a message: a way of delivering advice that might not always be welcome if delivered directly. It’s a way of suggesting caution or suggesting another approach that might be more appropriate. It often provides a very pithy yet diplomatic way of suggesting a different way of doing things. It can be a way of suggesting that a different path should be taken: a way of suggesting something for the other person to think about: something to really consider.
Thinking-out the implications of what we feel compelled to say before we actually say it, is the mark of a true professional.