The Vulcan hand salute and Jewish tradition
Nimoy had religious belief, though there is no indication to believe he had a Christian profession. He had been an active member of the Jewish community throughout his life, and could speak and read Yiddish, his native language. In 1997, he narrated the documentary A Life Apart: Hasidism in America, about the various sects of Hasidic Orthodox Jews.
In his 1975 autobiography I Am Not Spock, Nimoy wrote that he based the Vulcan hand salute on the Priestly Blessing performed by Jewish Kohanim with both hands, thumb to thumb in this same position, representing the Hebrew letter shin, which has three upward strokes similar to the position of the thumb and fingers in the salute. The letter Shin here stands for El Shaddai, meaning “Almighty (God),” as well as for shekinah and shalom. Nimoy wrote that when he was a child, his grandfather took him to an Orthodox synagogue, where he saw the blessing performed and was impressed by it.
The priestly blessing, also known as “raising of the hands” (Hebrew nesiat kapayim) or dukhanen (from the Yiddish word dukhan meaning “platform,” because the blessing is given from a raised rostrum), is a Jewish prayer recited by Kohanim. In Orthodox Judaism, Kohanim are Jewish priests descended from Aaron the High Priest, and according to Jewish tradition, have been divinely chosen to work in the Temple and assist others in serving God.
As stipulated in the Torah (Numbers 6:23-27 and Parshat Naso, the 35th Weekly Torah portion of the annual cycle), the Kohanim have a special duty to raise their hands and transfer the blessing of God to the people. The text of the Priestly Blessing recited by the Kohanim, which appears verbatim in the Torah, is:
“May the LORD bless you and guard you –
May the LORD make his face shed light upon you and be gracious unto you –
May the LORD lift up his face unto you and give you peace.”