- What's this one?
- The Ark of the Covenant.
- Are you sure?
- Pretty sure.

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

You can hear this line at 00:31:36 in the Blu-ray version of the movie.

Quote context

[...]

- Look after this for me, will you?

- Come on.

- Pagan symbols. Fourth or fifth century.

- Right. 600 years before the Crusades.

- The Christians would have dug their own passages and burial chambers centuries later.

- That's right. If there's a knight of the First Crusade down here, that's where we'll find him.

- What's this one?

- The Ark of the Covenant.

- Are you sure?

- Pretty sure.

- Watch out.

- It's petroleum. I should sink a well down here and retire.

- Give me the lighter.

- Oh, rats.

[...]