It's the ice cream man.

2 seconds sound clip from the Holiday (1938) movie soundboard.

You can hear this line at 00:05:04.366 in the Blu-ray version of the movie.

Quote context

[...]

- Goodbye, you comics.

- Good luck, Johnny.

- What's this?

- You said 843, didn't you?

- Yeah, but...

- I guess she must work here.

- Thanks, bud.

- It's the ice cream man.

- Oh, excuse me. Does a Miss Julia Seton live here? Miss Seton gave me this address.

- My name is Case, John Case.

- Miss Julia is expecting you, Mr. Case.

- Oh, then she does live here.

- Well, come in.

- Oh, I beg your pardon, but it's the usual custom for Miss Julia's callers to arrive at the front door.

- Oh, I'm sorry.

[...]