I'm not as big as you are.
4 seconds sound clip from the A Chump at Oxford (1939) movie soundboard.
You can hear this line at 00:26:00 in the DVD version of the movie.
Quote context
[...]
- Now we're getting some place.
- What are we going to do about the trunk? Think we'd better leave it here?
- Certainly not. We may never be able find it again.
- Well, I can't carry it, it's too heavy.
- All right, I suppose it's up to me, as usual.
- I'm doing all I can to help you.
[...]