He said it was Hogwarts business, very secret.
4 seconds sound clip from the Harry Potter and the Sorcerer's Stone movie soundboard.
You can hear this line at 01:18:19 in the Blu-ray version of the movie.
Quote context
[...]
- Blood?
- But, he got himself bitten, that's why he's limping.
- But why would anyone go near that dog?
- The day I was at Gringotts, Hagrid took something out of one of the vaults.
- He said it was Hogwarts business, very secret.
- That's what the dog's guarding. That's what Snape wants.
- Bit early for mail, isn't it?
- That's not just a broomstick, Harry, it's a Nimbus 2000!
- That's all right. I felt the same way before my first game.
[...]