I think I read he was working on a dig near Nineveh.
5 seconds sound clip from the The Exorcist movie soundboard.
You can hear this line at 01:39:11 in the Blu-ray version of the movie.
Quote context
[...]
- There should be a psychiatrist present, anyway.
- Merrin?
- I had a notion he was over in Iraq.
- I think I read he was working on a dig near Nineveh.
- Yeah, you're right Mike, but he's finished.
- He came back three or four months ago. He's at Woodstock now.
- What's he doing there, teaching?
- No, he's working on another book.
[...]