did Rashbam think Rashi was written b'ruch hakodesh?

Earlier in the week I mentioned R’ Dessler’s letter (4:31(2)) in which he argues that Chazal’s pshat in pesukim is just as much part of the mesorah as anything else, just we have license where we cannot understand or accept that pshat to read and interpret the text differently.  Learning pshat against Chazal is in effect a b’dieved situation, a response to the needs of “nevochim.”  R’ Menashe Klein, in his Shu”T Mishneh Halachos 5:165-169 (link) discusses this same issue at length and takes a very different view.  In a nutshell (it's a kuntres that goes on for a few pages) R’ M. Klein does not think Chazal ever meant their pshat as THE interpretation of any pasuk – they simply offer ONE interpretation of many, all of which are latent in the pasuk.  When meforshim are critical of a pshat brought by Chazal, the point is not that the interpretation is false -- the point is that Chazal's reading should be taken as derash and not pshat.  The argument is often over what level of meaning an interpretation is operating on, not whether that interpretation is true or false, as multiple true interpretations of the text are possible on different levels.  Revealing other meanings in the text is a l’chatchila, as this serves l’hagdil Torah.  (Judging from the comments and e-mail in response to last post, most people intuitively side with R' Menashe Klein.)  Two things struck me in his kuntres: 1) his tolerance of contextualization - an interpretation in Chazal/Rishonim may have carried particular meaning in its time or place, but in other periods other readings may be preferred (Rashbam at the beginning of Vayeishev's refers to "pashtus hameshachdim b'chol yom"); 2) not only can one learn pesukim is ways that are different than Chazal, but he writes that so long as the halacha is not impacted, one can do the same for Mishnayos and gemara. 

Another question he raises is whether Chazal and/or the Rishonim wrote everything b'ruach hakodesh.  I recently heard a speaker claim that regardless of whether other people believe Rashi was written b’ruach hakodesh, the Rashbam certainly didn’t think so.  I respectfully beg to differ with that reasoning.  In the famous tanur shel achna’I story, R’ Eliezer calls down various miracles to occur to prove that he is correct.  Surely public miracles are even better proof of Heaven’s assent than a private voice of nevuah or spirit of ruach hakodesh.  Yet we don’t pasken like R’ Eliezer.  The reason why is not because we have doubts about whether R’ Eliezer’s words are inspired –  it’s because that has nothing to do with the matter.  Torah is given to us to puzzle over with our own brains.  There is no contradiction between thinking that Rashbam felt his grandfather’s interpretation of chumash was written b'ruach hakodesh and Rashbam thinking that given the chance to revise, his grandfather would have updated that interpretation to read more like Rashbam’s own.

M’inyan l’inyan on the topic of pshat and derash, the Sifsei Chachamim on last week’s parsha asks a question that is so fundamental that you have to wonder why it didn’t come up earlier.  Rashi (24:17) offers two interpretations of “Vayakam s’dei Ephron”:

תקומה הייתה לה שיצאה מיד הדיוט ליד מלך.
ופשוטו של מקרא: ויקם השדה והמערה אשר בו וכל העץ לאברהם למקנה וגו'

We think of Rashi’s interpretation as “pshat;” he cites Midrash only to the extent that it helps explicate the plain meaning of the text.  So m’mah nafshach: if the pasuk is understandable according to the “peshuto shel mikra” (Rashi’s second interpretation), why does Rashi bother to quote Midrash?  And if the pasuk is not understandable according to the “peshuto shel mikra,” then why does Rashi cite it at all? 

The Sifsei Chachamim’s answer addresses that particular Rashi, but as he notes in his question, whenever Rashi cites multiple interpretations (even where he doesn’t label one pshat and one derash), the same question can be asked, so we need a general rule.    The question sounds fancy, but the answer is I think simple: whether a pshat is good or bad is not something that can be evaluated in absolute terms.  It’s a relative judgment compared to some other possible reading.  Whenever Rashi cites multiple interpretations, it’s because each one is lacking when weighed against the other.  Yes, the pasuk can be read according to “peshuto shel mikra,” but that comes at some expense; yes, the pasuk’s meaning is clearer in some ways if interpreted using Midrash, but that comes at some other expense (see S.C. for the strenghts and weaknesses of each pshat brought by this Rashi).  Whenever Rashi offers multiple interpretations, Sifsei Chachamim always looks for a weakness in each that is counterbalanced by the other pshat.  (Contrast that with, for example, the Sefas Emes, who will often show that both interpretations in Rashi complement each other to bring out a single hashkafic point.)