Posted by R. Berg on October 13, 2002
In Reply to: Touch wood posted by Shae on October 12, 2002
: It's an expression used when wishing good fortune to a person or venture. "Good luck at the job interview! Touching wood for you!" "I hope the weather is good for the barbeque tomorrow. Touch wood!"
: I've been told it refers to a medieval custom of touching a piece of the "True Cross," or of a reliquary that contained such a piece. Can anybody corroborate this?
That theory is around but not, it seems, proved.
Partridge, "A Dictionary of Catch Phrases":
'touch wood!' . . . For the various origins proposed for this phrase, you must consult the folklorists; the more, the greater fun. As merest layman and not all that seriously, I suggest that it originates in some half-buried myth about 'the Great God Pan', haunter of woods and forests. . . . Vernon Noble proposed, 1977: 'This is probably of ancient origin, or perhaps no further back than mediaeval times when relics were hawked about the country, including pieces of "the true cross". Those . . . unable to buy splinters . . . were probably allowed to touch them freely, as a gesture of piety and to bring them good luck or a blessing".
["Knock wood" or "knock on wood" is the US form. -- rb]