The guys putting on the big event were in a Charleston, South Carolina bar when they spotted Murray with another group.
One of the party planners got the nerve to ask Murray to say a few words, he declined.
But then, it got fun.
“Two minutes later, Bill f***ing Murray walks into the room and gives this speech," one of the astonished attendees told Deadspin.
The speech went like this.
"I'm gonna give you all this advice, because it's too late for this fellow. If you have someone that you think is the one, don't just sort of think, let's make a date, let's plan this and make a party and get married. Take that person and travel around the world. Buy a plane ticket for the two of you to travel all around the world and go to places that are hard to go to and hard to get out of. And if when you come back to JFK, when you land in JFK and you're still in love with that person, get married at the airport."
See the video by clicking here or watch it below. CAUTION: There is swearing in the video.