Could there be any connection between the word "Sisma" (a password) and the phrase, "open sesame?"
Should the word "Sisma" be spelled with an Aleph or a Heh?
What language did the word Sisma come from?
Let's first look at the word sisma. Surprisingly, I could only find one reference to it in all pre-modern Hebrew literature. It appears in Midrash Shmuel, a relatively late midrash (perhaps compiled around 1050), in the following quote:
אלולי שעשו סיסמא ביניהון
"unless they had agreed upon certain signals between themselves" (Jastrow's translation, who feels that the word is a plural - "fixed signals")
The word appears here with an alef at the end. I don't know when the word began to be used again in Hebrew - Ben Yehuda makes no mention of it in his dictionary, most likely because he viewed it as being a foreign (Greek) word. Whoever did reintroduce this word in to Hebrew, besides having a real knack for finding obscure words, chose to spell it with a heh at the end: סיסמה, and that is the spelling you will find in current Hebrew dictionaries. In modern Hebrew it also carries the meaning of "slogan, motto", in addition to the older sense of "signal, password".
As far as the etymology, Klein writes the following:
Greek syssemon (=signal), formed from Greek syn (=with, together with) and sema (=sign).He points out that is related to the word siman סימן, also meaning "sign, signal" and deriving from Greek sema.
Now while the English word "sesame" does sound similar to the Hebrew word sisma, they are not related. Sesame has the following etymology:
c.1440, probably from M.Fr. sisame, from L. sesamum (nom. sesama), from Gk. sesamon (Doric sasamon) "seed or fruit of the sesame plant," via Phoenician from Late Babylonian *shawash-shammu (cf. Assyrian shamash-shammu "sesame," lit. "oil-seed")
The Hebrew word for sesame, שומשום, also was borrowed from the Akkadian (Assyrian). How is the word pronounced? Ask the average Israeli, and they'll likely tell you sumsum. However, all the dictionaries, and vocalized editions of the mishna have shumshum. (For those readers who weekly recite Bameh Madlikin - have you noticed that the siddur has shemen shumshumin?)
Why the disparity between the official spelling and the "street" pronunciation? I don't believe that it comes from the Israeli version of Sesame Street - רחוב סומסום - Rechov Sumsum, deliberately spelled with a samech. The pronunciation predates the show by many years, and the name of the show reflects popular usage. (I assume the spelling was changed to make it easier for younger viewers. Having a sin / shin might have been too confusing.)
Rather, the pronunciation was likely influenced by a foreign language. Perhaps it came from the European languages, which as we noted derived from Greek (who did not have a "sh" sound, e.g. Shmuel -> Samuel). But I think it is more likely that modern Hebrew was influenced by the Arabic rendition of the word: simsim. As we've seen before, the Hebrew shin becomes "s" in Arabic (shalom -> salam).
And the Arabic simsim is the root of our phrase "open sesame". The phrase iftah ya-simsim was used to open a cave in Ali Baba and the Forty Thieves. (If you know the phrase as "Open Sez Me", you probably watched Popeye the Sailor Meets Ali Baba's Forty Thieves, which can be viewed here. He says the line at 14:39.)
What is the meaning of the phrase? There are a number of theories as to why simsim would have been the word used as the charm to open the gate. Perhaps the most interesting theory to me was presented by regular Balashon commenter Moshe M, who wrote to me that in addition to sesame, simsim can mean in Arabic "gate" (although it's a rare literary word). He heard this from Prof. Jonas C. Greenfield. Therefore the phrase meant "Open O Gate". (Ali Baba's own brother did not understand this apparently, and when he couldn't remember simsim, he tried guessing other foods, trying "Open barley", "Open wheat", and "Open chick-pea").
In this article, Greenfield shows us a Hebrew cognate for simsim meaning "gate". In Yishayahu 54:12, we find a difficult term:
וְשַׂמְתִּי כַּדְכֹד שִׁמְשֹׁתַיִךְ, וּשְׁעָרַיִךְ לְאַבְנֵי אֶקְדָּח; וְכָל-גְּבוּלֵךְ, לְאַבְנֵי-חֵפֶץ.
The JPS (new) translates it as follows:
"I will make your battlements of rubies,
Your gates of precious stones,
The whole encircling wall of gems"
The question is the translation of the word shimshotayich שמשותיך, offered by the JPS as "battlements". This seems to be the opinion of Rashi, quoting Midrash Tehilim, based on Tehilim 84:12. However, Radak, and Menachem as quoted by Rashi, say that shimsha שמשה here means "a solid, translucent piece, placed in the window, that lets the sun in". This is its meaning in modern Hebrew as well - "windowpane".
However, Greenfield writes that shimsha here means "gates" as well, which is parallel to shaar שער "gate", found in the second section of the verse.
I'll conclude with the observations about sesame by comedian Mitch Hedberg. (Warning: Contains mild language).