See the Vulcan “live long and prosper” sign on this tombstone from 1819? It really is, and this isn’t like the History Channel’s claims that aliens built the pyramids. But Spock, rather, borrowed from an actual human custom originating in Jewish tradition.
Leonard Nimoy’s hand signal is half of a sacred gesture made by the Kohanim, or Jewish priests. Stemming from Biblical tradition (see for instance Aaron brother of Moses getting the title of priest in Exodus 28: 1-4), the Kohanim performed many of the sacred rituals during the time of the Second Temple. After the Temple’s destruction, the Kohanim were still considered a special lineage but various Jewish denominations hold them in different regard. For instance, they play a role in synagogue services in Orthodox and sometimes Conservative Judaism but not Reform Judaism.
And one of the special blessings they do, as evidenced by tombstones such as these (and there are others that go back in time hundreds of years), is the gesture you see here. Two hands are held together with thumbs touching, which makes the Hebrew letter “shin” which is the first letter of one of God’s names. Facing the congregation, the Kohanim give a blessing with this gesture.
Star Trek’s Vulcans have deep roots indeed
Sources: Wikipedia for the tomb of Rabbi Meschullam Kohn _The cjn.ca_, “The Jewish Origins of the Vulcan Salute”, Lindsay Traves, Sept 22, 2019
