What is the origin of “touch wood” ? | What Why How & more…

What is the origin of “touch wood” ? | What Why How & more….

I never loose a bet “touch wood” or  I never loose any bets I ever make, “touch wood”.

Do these sentences seem similar to you in any manner? Well, the similarity is in the use of phrase “touch wood” . We use the phrase to ward off bad-luck but have you ever tried to find out why we do so or what is the origin of the phrase “touch wood” or “knock on wood”?