They had a signal set up, so he'd know the minute the ceremony was over.
6 seconds sound clip from the Goodfellas movie soundboard.
You can hear this line at 01:49:36 in the Blu-ray version of the movie.
Quote context
[...]
- Still, I never saw Jimmy so happy. He was like a kid.
- Jimmy was so excited, you'd think he was being made.
- He must have made four calls to Tommy's house.
- They had a signal set up, so he'd know the minute the ceremony was over.
- Let me look at you. You look lovely.
- What do you think, I look good?
- Listen, just be careful. Congratulations. I wish you lot of luck.
- Don't paint any more religious pictures, please.
[...]