Idiom
You can lead a horse to water but you can't make him drink.You can lead a horse to water (but you can't make him/it drink).
something that you say which means you can give someone the opportunity to do something, but you cannot force them to do it if they do not want to.I made all the arrangements, bought the ticket, and even took him to the airport, but he just wouldn't get on the plane. Well, you can lead a horse to water, but you cannot make him drink.