touch wood BrE
knock on wood AmE

He had a desire to knock on wood, but didn't want to in front of the men.

"Pirates are the one thing I've never had to deal with, knock on wood."

I hope my car makes it through the trip, knock on wood.

Knock on wood, my kids are wonderful, the marriage is great.

But people around here knock on wood whenever they say that times are good.

I've never had a virus or hard drive problem, knock on wood.

I got the most embarrassing night - knock on wood - out of the way.

"We're still knocking on wood; we haven't had a down year yet."

I, knock on wood, have never had anything crawl into my machine.

But weak magic was better than none at all, I always said, knocking on wood.