Toi toi toi
"Toi toi toi" is an expression used in the performing arts to wish an artist success in an imminent performance. It is similar to "break a leg" and reflects a superstition that wishing someone "good luck" is in fact bad luck.
Origin
There are many theories as to the origin of Toi toi toi as an idiom. In folklore it was used to ward off a spell or hex, often accompanied by knocking on wood or spitting. One origin theory sees toi toi toi as the onomatopoeic rendition of spitting three times, a common practice in many parts of the world to ward off evil spirits. Saliva traditionally had demon-banishing powers. Another theory claims the origin to be a threefold warning of the devil.Also from Rotwelsch tof and from Yiddish tov.