“Touching wood” expresses a superstition already practised in 660 BC. BC by the Persians.
Followers of Mazdeism(the Iranian religion named after its main god, Ahura Mazda), the Persians placed themselves under the protective power of Atar, the genie of fire, when they touched wood. The superstitious gesture of “touching wood” enabled them to ward off bad luck.
At the same time, the Egyptians were convinced that wood diffused a beneficial magnetism that protected them and gave them good health when they came into contact with it.
This expression, then linked to religion, was later also associated with Christians, who in the Middle Ages reproduced this gesture to protect themselves from adversity, in reference to the crucifixion of Jesus on a wooden cross.
Accompanied by the phrase “Touching wood”, this gesture is symbolic nowadays, as it is supposed to bring wishes for success, happiness and health.