(While examining a severed hand)
Sid: If the glove fits... This is reference to the famous: "If the glove doesn't fit, you must acquit" phrase associated with the 1995 O.J. Simpson criminal murder trial.
It's a pun with the expression If the shoe fits... wear it or If the cap fits... wear it, used to tell people you were not talking about them, but if they feel affected by what you are saying, then they should acknowledge the criticism.