The book. The witches used it to put the spell on him. Maybe there's a way in here to take it off.
10 seconds sound clip from the Hocus Pocus movie soundboard.
You can hear this line at 01:09:13 in the Blu-ray version of the movie.
Quote context
[...]
- Hi.
- Hi.
- Oh, my God. It's 5:00. My parents are gonna kill me. I should go.
- Yeah. Poor Binx. We owe him a lot.
- Yeah.
- Look, can we find some kind of way to help him?
- The book. The witches used it to put the spell on him. Maybe there's a way in here to take it off.
- Mmm, I don't know. Binx told us not to open it.
- Well, the witches are dead. What harm could it do?
- Do you want to hit me? Would that cheer you up? Okay. There you go.
[...]