who started the expression "knock wood?''?

Answer 1

It originated from the pagan belief that spirits lived in trees, and would grant you wishes when you communicated with them by knocking.

Several thousand years and cut down trees turned into coffee tables and computer desks later, knocking on wood still stuck around to whatever might have been in a tree.

Answer 2

Wood or trees have been seen to be an expression of nature or the greater spirit of the Universe for an unfathomably long time, even Christ on a wood cross is a manifestation of this, wood also floats and thereby keeps people safe from drowning when in water as well as providing an excellent fuel source for fire, material for homes, tools, weapons and so on. The practice of keeping in contact or "knocking" on wood is far too old a human practice to identify a specific moment when someone first referred to it. Human identification with wood is elementary to our early development as a species.

Answer 3

Here's one idea.

http://en.wikipedia.org/wiki/Knocking_on_wood

I'm not at all sure you will ever trace the origin. I do know it's Irish/Scottish/English. Now a days it's terribly hard to find much less talk about something that's just claimed by the Anglo/English race. It's not politically correct.

Good Luck on your Search!!
I'll be keeping an eye out for the answer

Answer 4

Anita Ward.

Answer 5

A guy had a "*****" and wanted people to knock it.