„BaLaschon” fragt in einem interessanten Artikel, was das Wort „Pessach” wohl tatsächlich bedeutet:

It might seem that the etymology of the word Pesach is so obvious that it doesn’t deserve an entry here. Pesach = “pass over”, no? Well, until I started researching it, I would have agreed. However, it turns out that the origin and meaning of pesach is one of the most complicated topics I’ve dealt with yet.

It is clear that Pesach is connected to the verb pasach ???. But what does pasach mean?

Both pesach and pasach appear for the first time in Shmot (Exodus), chapter 12:

?? ???????, ????????? ?????–?????????? ????????, ?????????? ????????????? ???????????? ??????????; ???????????? ????? ????????????, ?????? ???? ?????. ?? ??????? ?????? ????? ?????, ??? ?????????? ?????? ?????? ????, ?????????? ???-??????, ???????????? ???????; ?????-??????? ????? ????? ???????????, ??????????? ???????? ?????????.


Loewenstamm mentions an Arabic root connected to pasach which means to expand. (He brings the root in Arabic, but unfortunately I can’t read Arabic.) He states that the same verb also has the meaning “to save” (and therefore is another proof for him that the translation “to protect” is the most authentic.)

Eine interessante Ausführung… aber lest selber: Balashon - Hebrew Language Detective: pesach