The meaning of יִפֹּל מִצִּדְּךָ אֶלֶף

Summary: In which I encounter a novel peshat in davening, but still prefer my own.

Post: So, last Shabbos I was davening with an Artscroll siddur, and happened to glance over to the English side. I was surprised to see, in Tehillim 91:7:

ו מִדֶּבֶר בָּאֹפֶל יַהֲלֹךְ מִקֶּטֶב יָשׁוּד צָהֳרָיִם:
ז יִפֹּל מִצִּדְּךָ אֶלֶף וּרְבָבָה מִימִינֶךָ אֵלֶיךָ לֹא יִגָּשׁ:
ח רַק בְּעֵינֶיךָ תַבִּיט וְשִׁלֻּמַת רְשָׁעִים תִּרְאֶה: 

that yippol was translated as encamped. Thus, though 1000 are encamped to your side, and 10,000 to your right side, they will not reach you. These thousands to the left and right are sheidim and mazikin, and Hashem protects against them, such that they cannot reach you to harm you. Thus, the thousands are your enemies. This, they noted, was based on Rashi on the pasuk.

And indeed, Rashi on the pasuk writes:

"יפול מצדך אלף" - לשון חנייה כמו (בראשית כ"ה) על פני כל אחיו נפל

"מצדך" - משמאלך יחנו אלף שדים ואליך לא יגשו להזיק

Or, to utilize Judaica Press' translation of Rashi into English:

7. A thousand will be stationed at your side, and ten thousand at your right hand; but it will not approach you.

A thousand will be stationed at your side: Heb. יפל, an expression of encamping, as (Gen. 25:18): “before the face of all his brothers did he settle (נפל).”

at your side: At your left a thousand demons will be stationed, and they will not approach you to harm [you].

Note that he uses, as a prooftext, a reference to the very last pasuk in parashat Chayei Sarah, last week's parsha. So to locally, prior to given a midrashic explanation for the precise language choice, he explains based on another example that this is what nafal means:

18. And they dwelt from Havilah to Shur, which borders on Egypt, going towards Asshur; before all his brothers he dwelt.		יח. וַיִּשְׁכְּנוּ מֵחֲוִילָה עַד שׁוּר אֲשֶׁר עַל פְּנֵי מִצְרַיִם בֹּאֲכָה אַשּׁוּרָה עַל פְּנֵי כָל אֶחָיו נָפָל:
he dwelt: [נָפָל means] “he dwelt” as in (Jud. 7: 12):“Now the Midianites and the Amalekites and all those of the East dwelt (נֹפְלִים) in the valley.” Here Scripture uses the term נְפִילָה, (falling), whereas there (above 16:12) it states:“And before all his brothers he will dwell (יִשְׁכֹּן) .” Before Abraham died, “he dwelt” ; after Abraham died,“he fell.” - [Gen. Rabbah 62:5]		נפל: שכן, כמו (שופטים ז יב) מדין ועמלק וכל בני קדם נופלים בעמק. כאן הוא אומר לשון נפילה, ולהלן הוא אומר על פני כל אחיו ישכון (לעיל טז יב), עד שלא מת אברהם ישכון, משמת אברהם נפל:

So too the pashtan Rashbam:

פסוק יח 
על פני כל אחיו נפל - שכן כדכתיב: על פני כל אחיו ישכן.

On Chayei Sarah, Ibn Ezra will have none of this reinterpretation of nafal, and instead insists that there is an unstated object to this verb, that his portion fell in this location. Thus:

נפל -חלקו או גורלו.
או שרוב בני ישמעאל נוסעים ממקום אל מקום, כטעם אל הכשדים אתה נופל. וזה מעט רחוק, בעבור שאחיו במזרח ומצרים ואשור למערב לא"י.
ויתכן שהכתוב דבר על ישמעאל שמת בחיי אחיו, אחר שנפל כי לא ידענו סבת מותו.

What about in sefer Tehillim? Well, once again Ibn Ezra does not take nafal as "dwelt". Rather, it once again means fall. Thus:

[צא, ז]
יפול -הזכיר כי צל השם יסתירהו והוא יראה שיפלו לימינו ושמאלו רבים בבא הדבר, וזה טעם אליך לא יגש.

These who fell could well be his comrades, rather than his enemies. People are falling in battle, to the left and to the right, yet this same fate does not befall him.

So too Metzudat David:

מצודת דוד

"יפול" - אף אם בעת הדבר יפלו אנשים רבים מצדך ומימינך ומכל מקום אליך לא יגש הדבר ההוא ולא יזיק לך

This is how I always read the pasuk. And looking back on it, now, in context of battle, I still prefer this reading. And not just because as a rationalist, I don't believe in the existence of invisible demons surrounding me. Rather, I think the perek flows much better as I've always read it.

I would note that even if nafal can mean "dwelt / encamped" in certain contexts, that does not mean that we should select that meaning everywhere. For instance, Rashi and Rashbam do not explain every occurrence in Tanach as "encamped" rather than "fell". There must be other textual cues to select this reading. In this case, perhaps it is yigash, such that looking for an actor and failing to find it, one happens across the ones on the left and the right. But see how Metzudat David explains this missing, implicit element.