In this video, the late actor Leonard Nimoy explains how he decided to use the gesture for his Star Trek character while looking for a "special" Vulcan greeting.
The salute is actually based on a Jewish blessing performed by Cohens - believed to be the descendent of biblical priests - in a process called dukhanening. For the majority of Jews living outside of Israel, dukhanening is only performed on high holy days.
We did it as a Vulcan greeting. And boy that just took off through the culture. It was amazing. Within days of it going on the air I was getting it on the street, people doing this to me, waving to me.
Most people to this day still don’t know what it’s all about.
Nimoy first saw the sign when in synagogue as a child. The hand shape is used to symbolise the Hebrew word shin which stands for Shaddai, meaning god.
My father told me not to look… I peeked
I had no idea what was going on but the sound of it and the look of it was magical