Context - One might use it in the following situations:
"An employee has an argument with their boss and a dispute follows." (they get fired a few weeks later)
"A student having an argument with his teacher over his grades takes the problem to the headmaster." (the headmaster doesn't want to get into it and says the teacher is right)
"Workers go on strike for a week, get no raise and are considered absent from work."
You can say it to your son/daughter as a prediction: “Be careful mate, remember…(the saying)…
And you can also say it when he/she comes to you for comfort and support: “I told you, mate, they say that........(the saying).