This is to build up your strength and your resistance.
3 seconds sound clip from the Shaolin Temple Strikes Back (1981) movie soundboard.
You can hear this line at 00:25:30.600 in the DVD version of the movie.
Quote context
[...]
- All I do is either work or stamp my feet. It's been over six months now. What good will this do me?
- Ah, it's only been six months since you became a monk and already you're bored with it?
- Huh? Just working our feet takes three or four years?
- This is to build up your strength and your resistance.
- Ah, hey, you're roasting a chicken.
- Yes, would you like to have some too?
- Ah, you're all monks. You're not allowed to eat meat, am I right?
- Then I won't give it to you. And you can't blame me.
- No, we won't. It's not your fault.
[...]