He has made it all so clear,
it takes a long time to catch the point.
If you realize that it's foolish to look for fire with fire,
the meal won't take so long to cook.
Mumonkan, Zen and Zen Classics, Volume 4
Mumon is an odd fellow. I've always thought so. But when he says "look for fire with fire", he illuminates everything.
There isn't enough humor in Zen these days, not enough irreverence. Mumon was a great Master of foolish irreverence. He never saw a statue he didn't draw a mustache on. People will say that Zen isn't foolish. They will say that the freeing of the mind from suffering, from the Law of Causality, that this isn't a joking matter. But since they aren't Zen Masters, what do they know?
There is an art to joking about the serious things without setting aside their seriousness. Mumon had a gift for it. If you doubt me, turn off all your lights, light a kitchen match, and search your house for matches.