I'll bet your mother told you that too.
5 seconds sound clip from the Miracle on 34th Street (1947) movie soundboard.
You can hear this line at 00:09:54 in the Blu-ray version of the movie.
Quote context
[...]
- Oh, your mother and father must have told you a fairy tale.
- No. My mother thinks they're silly.
- I don't know whether my father thinks they're silly or not. I never met my father.
- You see, my father and mother were divorced when I was a baby.
- Well, that baseball player certainly looks like a giant to me.
- People sometimes grow very big, but that's abnormal.
- I'll bet your mother told you that too.
- Hello. Uh, I'm Susan's mother.
- Yes, I know. Won't you come in? Susie's told me quite a lot about you.
- Yes, I know. Susan's told me quite a lot about you too.
- Won't you have a cup of coffee? You must be half-frozen standing out...
[...]