וְהַמְּדָנִים מָכְרוּ אֹתו אֶל-מִצְרָיִם לְפוֹטִיפַר סְרִיס פַּרְעֹה שַׂר הַטַּבָּחִים.
And the Midianites sold him to Egypt, to Potiphar, one of Pharoah’s noblemen, the minister in charge of slaughtering.
Genesis 37:36
Ramban argues with Rashi on this verse, regarding the meaning of שַׂר הַטַּבָּחִים, “the minister in charge of the slaughterers”. Ramban instead prefers Onkelos’s rendition, as רב קטוליא, which roughly translates to “chief executioner”.רש”י:הטבחים: שוחטי בהמות המלך.Rashi:
the slaughterers: the slaughterers (shechters) of the kings domesticated animals.
I think we may find a clue to how to tip the balance of this debate, by looking at a possible meaning for Potiphar’s name. (He is one of the few Egyptians for whom we will actually see a proper name.)
Potiphar’s name,”פוטיפר” seems similar to the name of one of Pinchas's ancestors, as we see from Parshas VaEra:
The name, פוטי-אל (Putiel) has the same prefix as פוטי-פר. In his comment on the above verse, Rashi explains the origin of this name:
וְאֶלְעָזָר בֶּן-אַהֲרֹן לָקַח-לוֹ מִבְּנוֹת פּוּטִיאֵל לוֹ לְאִשָּׁה וַתֵּלֶד לוֹ אֶת-פִּינְחָס אֵלֶּה רָאשֵׁי אֲבוֹת הַלְוִיִּם לְמִשְׁפְּחֹתָם.And Elazar, the son of Aharon took a wife from the daughters of Putiel, and she bore him Pinchas...
רש”י:מזרע יתרו שפטם עגלים לעבודת אלילםRashi:
("From the daughters of Putiel" means she was) a descendant of Yisro who fattened calves for worship of false gods.
Rashi is apparently telling us that פוטי (Puti) is derived from the verb פטם (Patam), which means fatten (an animal). And of course אל is the generic term for a god. If we dissect Potiphar’s name the same way, it is פוטי + פר, or in English, fatten + bull. So it seems that just as Yisro’s name (or that of one of his descendants) was called by his vocation -- one who fattens cows -- so too Potiphar’s name can be translated as one who fattens bulls (or cows).
Based on the foregoing, we might reason that “the one who fattens bulls” is a name especially suited to the שַׂר הַטַּבָּחִים, the slaughterer of the king's animals, which is Rashi’s interpretation. So perhaps this is an argument in favor of Rashi, and against Ramban (and Onkelos).
One final point: Rashi again mentions this name for Yisro in his commentary on Parshas Yisro (Exodus 18:1):
רש”י:
שבע שמות נקרא לו רעואל יתר יתרו חובב חבר קיני פוטיאל...
Rashi:Yisro had seven names: Reuel, Yeser, Yisro, Khovav, Khever, Kaini, Putiel...
Although Rashi explains the meaning of the other names, he skips over discussing פוטיאל in this comment. This could be for one of two reasons: since he already translated this name in an earlier comment, he felt it would be redundant to mention it again, or, because this name is a degrading name for Yisro, he felt it would be inappropriate to elaborate it in Parshas Yisro, which is widely seen as a moment of praise for Yisro. (To lend further credence to the second idea over the first, Rashi does repeat his explanation of the meaning of Putiel in his comment in Parshas Pinchas, where Pinchas’s lineage is mentioned again.)
