In Highlander II: The Quickening, General Katana confronts Connor MacLeod in a chapel. After he reminds him that they can't fight because it's holy ground, he says this:
Ashes to ashes,
dust to dust.
If you don't take it out and
use it, it's going to rust.
What's he talking about? To be honest, it sounds like innuendo, but that seems really odd in context (unless they're trying to make him vulgar like the Kurgan was in the first movie).