Maimonides (Hilchot Temidin Umusafin 5:9) describes the shape of the Showbread as follows –
“Each each loaf is מרובעת square as it says “Lechem Panim” (Exodus 25:30) that it should have many “panim” [sides]. The length of each loaf is 10 tefachim/handbreadths and its width 5 tefachim/handbreadths and its “ruma” (height) is 7 eztbaot/finger widths. The Shulchan (Table) is 12 tefachim/handbreadths long and 6 tefachim/handbreadths wide. You place the length of the bread across the width of the Table. It turns out that loaf is sticking out 2 tefachim/handbreadths one one side and 2 tefachim/handbreadths on the other side and you fold כופל the parts sticking out on either side and there remains a space in the center between the two sides. Thus you place one loaf on top of another until you have a stack of 6 loaves and similarly on the side of the other stack, 6 loaves”.
From the use of the term “square” (in fact the bread is obviously not square, but rectangular according to the given length and width, however the term מרובעת is inclusive of all right angled shapes, squares and rectangles), some commentators, like the Kesef Mishna (ibid.) infer that Maimonides is ruling (halacha lema’aseh) according to the opinion of Rebi Hanina in his debate with Rebi Yohanan (Talmud, Tractate Menahot 94b) regarding the shape of the Showbread, that it was a rectangular shaped Teiva Perutza (open box).
The Kesef Mishna comments that if this is the case, it requires further investigation on Maimonides, because that conflicts with the conclusion of the Talmud there “תניא כמד"א דכמין ספינה רוקדת היה לחם הפנים, we learn in a Berayta according to the opinion that the Showbread was shaped like a Sfina Rokedet (dancing-ship)”, i.e the end result of the debate about the shape was according to R. Yohanan, that the Showbread was round.
In fact even the verse in the Torah hints that the Showbread was rounded “And you shall take solet (semolina) flour and you shall bake 12 loaves חלות, each loaf will have 2 isaron measures etc.” (Leviticus 24:5). Onkelos, the famous translator of the Torah translates the word חלות loaves as גריצן (gritzan). The first time the term “gritzan” is used by Onkelos in the Torah is in Genesis 18:6 in reference to the episode where Abraham told his wife to hurry and knead and make “uggot” (for the three Angels), which Onkelos also translates as גריצן (gritzan). The commentaries are unanimous that “uggot” are round (re: uggot matzo and Choni Hame’agel, etc.).
The Kesef Mishna proposes that perhaps Maimonides preferred the rectangular shaped opinion of R. Hanina because R. Hanina had seniority over R. Yohanan and was considered a Tanna (the generation of the Mishna). If indeed Maimonides gave preference to R. Hanina based solely on his age and seniority, then this contradicts another ruling of Maimonides (Tractate Gerushin 7:5) where he rules in favor of R. Yohanan and against R. Hanina (Yad Malachi תקנ"ז, Sdei Chemed 8:90, Maharitz Chayot Gitin 5).
Continuing the assumption that Maimonides ruled according to R. Hanina and the Teiva Perutza (open-box) rectangular shape, other commentators (Lechem Mishna (ibid.), Shoshanim LeDavid 11:41) also try to find a reason why he did so. Perhaps because the opposing method of the rounded Sfina Rokedet (dancing-ship) shape appears to be more complicated in the debate (Menahot 94b) and he finds the question and answer back and forth of the Sfina Rokedet (dancing ship) shape there lacking in clarity (also see the length of the Tosfot there, indicating its complexity). Perhaps Maimonides felt that the Teiva Perutza (open-box) rectangular shape was more intuitive, geometrically speaking.
In truth the Teiva Perutza (open-box) is simpler to understand - if you are trying to figure out how the shapes looked (if, on the other hand, you already know how the rounded Sfina Rokedet (dancing-ship) shape looked, in hindsight it is very simple, but trying to figure it out the other way around is very complicated. See the article “The precise form of the Sfina Rokedet Shape”). Almost all the commentators and printed editions of the Talmud have troubled describing the Sfina Rokedet shape. The shape of the Teiva Perutza (open-box) is easy to figure out.
Either way, the assumption in the commentaries is that Maimonides, when he stated “מרובעת square” was ruling that the shape of the Showbread was the rectangular Teiva Perutza (open-box) and all the effort is devoted into finding out why.
But, what if Maimonides was not ruling according to the Teiva Perutza (open-box) shape at all?
Unlike Rashi, who specifically states his opinion that the Showbread was shaped like a Teiva Perutza (open-box) (Exodus 25:29), Maimonides does not use specific language at all, in particular he makes no specific reference to the terminology used in the debate (Menahot 94b), but rather a more general description “מרובעת square”. Why doesn’t Maimonides just come out with it, like Rashi and say Teiva Perutza (open-box) or Sfina Rokedet (dancing-ship)?
If you closely examine the phraseology of Maimonides in his ruling (ibid.), you will see that he phrases it, in fact almost copies it verbatim, from the oldest existing written source that describes the shape of the Showbread (Mishna Menahot 11:5)-
“Rebi Meir says the Table is 12 [tefachim] long and 6 [tefachim] wide. The Showbread is 10 [tefachim] long and 5 [tefachim] wide. You place the [Showbread’s] length across the width of the Table and fold it 2 [tefachim] on this side and 2 [tefachim] on this [other] side …..”.
Maimonides in his rulings is very careful to copy the sources as they originally appear and only adds or alters a word if he thinks it better explains or clarifies a point. What he does not do, is leave something out by mistake. If something is appears to be missing, then there is a specific reason for it.
Maimonides adds the word מרובעת square, that does not appear in the Mishna above and it is undeniable that the Showbread begins as a square/rectangle, 10X5 tefachim/handbreadths. Nobody disputes this and it is categorically stated in the Mishna. When Maimonides uses the term מרובעת square, he is undoubtedly referring to this rectangular basic shape – before it was folded - since the term מרובעת square precedes the description of length and width. If Maimonides intended to convey that the final shape of the Showbread, after folding, was מרובעת square, he would have stated מרובעת square after the description of the folding and not before and might have even added for example “מרובעת square like a Teiva Perutza”, but he doesn’t.
In fact Maimonides makes no reference at all to the debate (Menahot 94b) between R. Hanina and R. Yohanan, omitting from his ruling any terminology used there.
The oldest commentator on Maimonides, Rabbi Yosef Korkos, in his commentary on this ruling, similarly omits any reference to the above debate entirely (my thanks to Rabbi Azaria Ariel Shlita from the Temple Institute for informing me of this).
If this is the case, that Maimonides totally ignored this debate in his ruling, the question is why? If you are making a ruling, be specific, like Rashi and state categorically what the final shape was after the folding described in the Mishna (ibid.)
The answer to this question is that there is a world of difference between Rashi’s commentary on the Torah (Exodus 25:29) and Maimonides’ rulings in Hilchot Temidin Umusafin above. The one is commentary and the other is halacha (rulings). If Maimonides omitted to specify which of the shapes the Showbread ultimately ended up as, the Teiva Perutza (open-box) or the Sfina Rokedet (dancing-ship), it is because they have no bearing on or relevance to the ruling. From a halachic (ruling) standpoint, the only requirements were those stated in the Mishna above, that the bread was laid with its length across the width of the Table and was then folded up on either side by 2 tefachim/handbreadths. If the bread then had a flat base or a rounded base (this is essentially the only difference between R. Hanina and R. Yohanan – see article “What is between R. Hanina and R. Yohanan?”), that is irrelevant in terms of the halacha (ruling). It was not a requirement in terms of the halacha that it should have a flat base or a round base and if you made it either way, it would have been acceptable.
This is the way the Chazon Ish (Menahot 42, pg. 80) understands Maimonides –
“And it appears that according to the letter of the law of the Showbread, it is possible to make it in any shape that you like and the debate only addresses how it was customarily made”.
Perhaps the Chazon Ish’s expression “any shape you like” is a little to broad, after all there are certain constraints regarding the shape stated in the Mishna and ratified in Maimonides ruling, for example - the bread had to be folded on both sides by 2 tefachim/handbreadths, but what I think the Chazon Ish is trying to say, is that - within those constraints – it could have been any shape, with a straight base, a curved base, etc.
This would reconcile the Kesef Mishna’s question on Maimonides that he says “requires further investigation”, as he assumes that Maimonides is addressing the debate between R. Hanina and R. Yohanan. However if Maimonides is not addressing it at all, then there is no question that requires further investigation.
The fact that Rashi states specifically Teiva Perutza (open box) in his commentary (Exodus 25:29), some regard as ratification that Maimonides also ruled that the Showbread was a Teiva Perutza when he states מרובעת square in the halacha (ruling) above. I have proved above that this is most likely not the case.
Prof. Zohar Amar, Bar Ilan University is of the opinion that the two shapes Teiva Perutza (open-box) and Sfina Rokedet (dancing-ship) perhaps reflected diffferent periods in history. It may have been that in the 1st Temple the shape was Teiva Perutza (open-box) and in the 2nd Temple it was the Sfina Rokedet (dancing-ship), as reflected by the Antigonus II pruta coin.
This theory is a reflection of the Chazon Ish's interpretation above.
I also believe the Chazon Ish’s understanding of Maimonides ruling is the correct one and that Maimonides did in fact not even address the debate in Menahot 94b and that in terms of halacha (ruling) it was irrelevant.