I should have mailed it to the Marx Brothers.

4 seconds sound clip from the Indiana Jones and the Last Crusade movie soundboard.

You can hear this line at 00:51:00 in the Blu-ray version of the movie.

Quote context

[...]

- What book?

- You have the diary in your pocket.

- You dolt! Do you think my son would be that stupid that he would bring my diary all the way back here?

- You didn't, did you? You didn't bring it, did you?

- Well...

- You did.

- Look, can we discuss this later?

- I should have mailed it to the Marx Brothers.

- Will you take it easy?

- Take it easy? Why do you think I sent it home in the first place? So it wouldn't fall into their hands!

- I came here to save you!

- Oh, yeah? And who's gonna come to save you, Junior?

[...]