We don't. It's history.
4 seconds sound clip from the The Sandlot (1993) movie soundboard.
You can hear this line at 00:25:55 in the Blu-ray version of the movie.
Quote context
[...]
- You guys were leaving, so I just thought I'd hop the fence...
- If you were thinking, you wouldn't have thought that.
- Then how do we get the ball back?
- Kiss it.
[...]