Priests were metal-reinforced overshoes. They saved your soles. This is an Assassin joke.

“Magrat wondered what it was like, spending your whole life doing something you …”

“Everyone has gods. You just don't think they're gods.”

“The mere fact you're delivering any will help, I'm sure," said Professor Pelc, …”

“People couldn't become truly holy, he said, unless they also had the opportunit…”