This was a scene in the show The Big Bang Theory, season 2, episode 9.
Sheldon and Penny are having a conversation on the staircase, which is as follows:
Sheldon: Of the handful of women Leonard's been involved with, she's the only one I have ever found tolerable.
Penny: Well, what about me?
Sheldon: The statement stands for itself.
What does Sheldon's last statement—"The statement stands for itself"—mean?