The following point now claims our attention. The account of the six days of creation contains, in reference to the creation of man, the statement: “Male and female created he them” (i. 27), and concludes with the words: “Thus the heavens and the earth were finished, and all the host of them” (ii. 1), and yet the portion which follows describes the creation of Eve from Adam, the tree of life, and the tree of knowledge, the history of the serpent and the events connected therewith, and all this as having taken place after Adam had been placed in the Garden of Eden. All our Sages agree that this took place on the sixth day, and that nothing new was created after the close of the six days. None of the things mentioned above is therefore impossible, because the laws of Nature were then not yet permanently fixed. (Guide II:30)
R’ Daniel Eidensohn (author of “Yad Moshe”, an index to the Igros Moshe, and “Daas Torah”, a resource book of rishonim on various topic in Jewish thought) collected the following commentaries on this chapter.
It is quite clear that the Rambam is understood to say that sequence during creation refers to relationships, not time. Time itself is a creation, and its meaning was not fully established.
The 9th question concerns that which is mentioned in the Moreh Nevuchim. Rambam notes that time can not exist without the movement of the celestial spheres and the the sun and moon. However this raises the question as how there could be time before the fourth day when the celestial spheres and sun were created? The Rambam answered this question by asserting that in fact the spheres and the sun were created on the first day. Thus time existed for the first 3 days in the same manner as it existed on the subsequent days. He explained that in fact everything — both the Heavens and the Earth — were created on the first day. The Rambam cited Chazal that the word “es” indicated that the creation on the first day included everything associated with the Heavens as well as everything associated with the Earth. He also cited the gemora (Chulin 60a) that everything that was created was created in its final form. He also cited another statement of Chazal that the Heavens and Earth were created simultaneously. Thus the Rambam believed that the work of Creation happened all on one day and was not divided amongst six days. He claimed that in a single moment of creation everything came into existence. He explained that the reason for the Torah stating that there were six days of Creation was to indicate the different levels of created beings according to their natural hierarchy. Thus the Rambam does not understand the word day to be a temporal day and he doesn’t read Bereishis to be describing the chronological sequence of creation…. This is the view of the Rambam which he considered as one of the major secrets of the Creation. In fact he tried hard to conceal this view as can be seen in his words in Moreh Nevuchim (2:30). In spite of his efforts the Ralbag, Navorni and the other commentators to Moreh Nevuchim uncovered his secret and made it known to the whole world…. However, despite the Rambam’s greatness in Torah and the apparent support from Chazal, this view of the Rambam is demonstratably false….
The Abarbanel is clear in question 5 that the Rambam certainly held of creation yeish mei’ayin (ex nihilo), that he was not totally declaring creation an allegory — only the notion of a progression of events over the 6 days of time:
Behold you see that the opinion of the Rav [ie the Rambam -mi] was not that all of the story of creation was an allegory, but only a small part of it. All that is mentioned regarding the activity of the six days, from the creation of the heavens and the earth, and all of the phenomena, and the creation of Adam and his wife, up until “vayechulu” [the first Shabbos -mi], have no allegory whatsoever for everything was literal to him [the Rambam]. Therefore you will see that in this very chapter, no. 30 in the second section, in all which the Rav has explicated regarding the activity of the six days, he did not make an allegory or a hint at all. Rather, he did the exact opposite, for he made a concerted effort to support the doctrine of creation ex nihilo and accepted all of the verses literally…
Shem Tov (Moreh ad loc):
Just as G-d is an absolute unity, His actions are also unified and from His organization came out the sequence of Creation. At the start — time was created simultaneously with the rest of Creation. It is incorrect to say that Creation began at the start of time. Consequently creation consisted of entities that were separate and distinct and prioritized — which is not a reflection of G-d Who is an absolute unity. Their prioritization is the result of their nature as to what their purpose and causal relationship is in combining and interacting with other things. Therefore it only in describing their level in reality that we say Day One, Day Two — but not that they were created in this sequence. Thus the Rambam’s explanation rejects the literal meaning of the Torah verses. He asserts that everything was created simultaneously. It is only as a reflection as to their purpose and importance does the Torah say first second and third and the rest of the days.
Aqeidas Yitzchaq (Bereishis sha’ar 3):
The Rambam in Moreh Nevuchim gives the reason for Torah saying that there were days in the Beginning by citing the gemora in Chullin(60a). There it states that the products of Creation were all created complete. In other words all of creations was created at the first instant of creation in their final perfect form. Thus he says that the Creation description is not describing the chronological sequence of events but the days are simply serving to indicate distinctions in their levels and to inform of of the hierarchy of Nature. This was a major esoteric doctrine of the Rambam concerning Creation as those who are understanding can discern from Moreh Nevuchim 2:30) which is devoted to this issue. However the Ralbag publicized it in detail and expounded it thoroughly….
Ralbag (Milchemes Hashem book IV, II8):
You already know from the preceding that the generation of the universe by God occurred in no time, since [its generation] was from nothing to something. Thus, our Rabbis maintain that the heavens and’ the earth were created simultaneously. As it is said in the Chapter [called] “One Does Not Interpret”: “Both were created as one. For it is said, ‘Yea, Mine hand hath laid the foundation of the earth, and My right. hand hath spread out the heavens; When I call unto them they stand up together. “‘ It is therefore evident that the description of creation as being completed in six days is not to be construed as [implying] that the first day preceded the second, for example, by one [whole] day [i.e., twenty four hours]. Rather, they said, this is in order to show the priority amongst various created things. For example, the movers of the heavenly bodies are causally and by nature prior to the heavenly bodies, whereas the latter are causally and by nature prior to the elements and to that which is generated from them. Now, the elements are prior to that which is generated from them according material priority, and the compounds of the elements are also [related] to each other by this kind of priority.For example the plant is prior to the animal; and similarly the imperfect animal is prior to the perfect animal. In the same way, an aquatic animal is prior to a flying animal, and the latter is prior to a walking [i.e., terrestrial] animal while the latter is prior to the rational [animal, i.e., man]. For an aquatic animal produces an imperfect egg, whereas the bird produces a perfect egg; the walking animal, however, produces a living animal in its own body. For this reason Aristotle says in The Book, of Animals that the bird is more perfect than the aquatic animal and the walking animal more perfect than the bird. And there is no doubt that man is the most perfect animal amongst the walking animals.
Alschich (Bereishis 1:1):
Bereshit Rabbah 1 comments on the repeated use of the word “es”, i.e. “es hashamayim”. The first “es” is supposed to include the solar system, whereas the second “es” is a reference to all the vegetation on earth. This sounds perplexing, seeing that vegetation is specifically reported as having been created on the third day, and the galaxies are reported as having been created on the fourth day; so how could they have been included by the words “es” at the very beginning? The answer is that the author of the Midrash did not want foolish people to think that what we know as a time-frame was indispensable for the development of the physical universe from its inception to its completion. We must not be allowed to think that G-d required six days to accomplish what He did. This is one reason why G-d did not say in the Ten Commandments that He created the universe in six days The words used are “six days,” as distinct from in six days, etc. 20,11) The idea conveyed in that verse is that G-d created these six day simultaneously with creating heaven and earth. The Midrash goes on to tell us that the word “es” in that verse is to alert us to the fact that heaven already contained all the elements for the galaxies, etc., and that “earth” already contained beneath the surface all the elements of vegetation, etc. These elements became revealed only at a later stage during the creative process.
Rav JB Soloveitchik (unpublished lectures on Bereishis, #7):
Indeed, one of the most annoying scientific facts which the religious man encounters is the problem of evolution and creation. However, this is not the real problem. What actually is irreconcilable is the concept of man as the bearer of a divine image and the idea of man as an intelligent animal in science. Evolution and creation can be reconciled merely by saying that six days is not absolutely so, but is indefinite and may be longer. Maimonides spoke of Creation in terms of phases and the Kabbalah in terms of sefiros, the time of which may be indefinite. However, our conflict is man as a unique being and man as a friend of the animal. Science can never explain how being came into being, for it is out of the realm of science, while the Bible is concerned with the problem of ex nihilo. Aristotle could not accept evolution because he believed in the eternity of forms.
(With thanks to Rabbi Eidensohn for permission to use his research.)