You didn't know, OP. At least now you know something interesting about a different religion and culture. Plus he's a monk, I'm sure he understands that you didn't know and isn't mad or otherwise upset with you.

Sounds to me like the situation sucks more for him. :-/

more like F his Life

I'm trying this comment one more time. sorry if it's a duplicate... Personally, I think that if you visit another country you have an obligation to learn at least as much as you need to be polite and respectful of their culture and customs. It's really not that hard to learn a few useful words like please, thank you, do you speak English, etc. I've found that people really appreciate the effort, and are much friendlier and helpful, even if you end up butchering the language--at least you tried. Religion is a particularly delicate issue. I've been to churches all over Europe, and although I'm Jewish, I would never walk into a church inappropriately dressed, like I've seen so many tourists do. How hard would it have been for the OP to simply ask the monk if he/she could sit down? That's simple courtesy anywhere. Ignorance is not an excuse for rudeness.

That religion is stupid