The basic text version used in the present on—volume Rambam is based on Yemenite manuscripts edited and proofread by my teacher and Rabbi, Rabbi Kapakh of blessed memory. The nature and quality of the Yemenite manuscripts have been long acclaimed. Here are some of the praises lavished by the Frenkel edition on these manuscripts and their reliability (as presented in their introduction to their "alternate versions collection"):
“We wished to provide a short note regarding the nature of the sources: The Yemenite books are the most authoritative of all. It is well known that the sons of Yemen have excelled more than all of Israel's other tribes in their precision and wondrous care not to change anything in the texts they have received. It is also well known that the books of our Rabbi were their main scholarly fare for generations. Their books testify to the fact that their copiers did not dare to change a single letter from what lay before them. It is also evident that the copiers had greater Torah knowledge than their peers in other lands of the Diaspora, where most copiers where hired laborers rather than scholars. Anyone who wishes to discuss the precise implications of our Rabbi's choice of words would do well to adopt the Yemenite version as his main staple, as presented here in the "alternate versions collection" section. (1)

To this one should add that the sons of Yemen, always determined the Halacha according to the Rambam (except for a few exceptions that a boy can count). The ties of the sons of Yemen to the Rambam and his ties with them, require no proof. The Rambam's text version was the basis of practical Halacha among the sons of Yemen, a lively well-spring of tradition handed down through generations. As the Rambam himself states: "The wisdom received through tradition and the practical actions of Halacha are great pillars of the teaching, and are worthy as foundations" (the Halachot of Shemita and the Jubilee, X, 6). The Rambam's prayer format (presented at the end of the Book of Love) is also based on Yemenite manuscripts, and reveals almost perfect identity with the ancient version of the Yemenite prayer book!

Rabbi Kapakh’s edition, which is not based on a single manuscript, nor on a majority of manuscript, but rather on a scholarly and well-founded determination among manuscripts - can assuage the reservations of the Frankel edition’s alternative versions editors when they write that: “it should be noted that in the Yemenite books, one usually finds the first version written by our Rabbi in his book, rather than the language corrected by our Rabbi after he completed his book and it became widespread". Nevertheless, in places where various editors differ as regards the correct version, I have recorded the additional version in the margins of the Halacha, where the reader may easily see it, without assigning any determination or evaluation, so that the dear reader may judge for himself the version that seems most preferable. Thus, the present edition provides an incontestable response to this reservation too, therefore constituting a reliable edition acceptable to all..

As we compiled this edition, we also had before as a facsimile of the Oxford Huntington 80 manuscript, which is an excellent manuscript version of the books of Mada and Ahava (Science and Love) and bears the authorization of the Rambam himself at the end of the book of Ahava, before the arrangement of the prayers, in his own sacred handwriting: "proofed from my book, I Moshe son of Rabbi Mimon of blessed memory". It seems that this manuscript hand been copied from a second or third copy, and was brought for proofing and comparison with the Rambam’s book, yet this book is certainly unlike the book that was "in the Azara of the Temple" and is not bereft of all errors (see the Rabbi Shilat's edition). The virtue of this edition is in its proofing remarks, most of which were done by passing a line above the words or over the words themselves in order to cross them out (2) but who can tell which proofreading comment was carried out as a comparison and which was added years later?! Thus, refraining from deciding one way or another, until we find the appropriate version through perusal and study of each proofing comment, we have left our version in its original state, and directly beside it, we have recorded the Oxford manuscript version. It should be noted that a great many of the corrections and proofing comments carried out in the Oxford manuscript are already part of the Yemenite manuscripts. In such cases, I made no comment, nor have I made any comment on version changes that do not constitute a semantic change.

Using computerized tools, and with the gracious permission of their respective editors, this manuscript was compared in a comprehensive and thorough fashion with precise manuscript versions that have been published in our generation: The “Yad Pshuta” edition, the “Rambam Meduyak” edition, the “Machon Mamreh” edition, and with the Frenkel edition in their comments and their "alternate versions collection" based on manuscripts. In this way, we were able to suspect many typos in the Kapakh edition, whether through lost or added words, switches of similar words or a number of skipped words. However, even when our suspicions found support in the alternative text versions provided by the Frenkel edition, we corrected the error only after being absolutely confident that this was indeed the correct version, a confidence that we secured through perusal of the very manuscripts used by Rabbi Kapakh himself (see the Yeshiva website for additional details). Nowhere did we ever change the main text version based on conjecture, if we did not find a reliable manuscript supporting such a proposed change. The comparisons we conducted also allowed us to mark certain significant version changes, although not those of final MEM or NUN, male or female grammatical construction, etc.(3) We took care to focus on the purpose for which this edition was created, and knowing that any change in text version "steals" attention, we asked ourselves if a proofing comment was worthwhile. (4) We hope that we have done what we set out to do and done it well, and this can be easily seen – especially as the comparisons we conducted indicate that the number of places with considerable and fundamental changes is in fact very small – for in our edition, the Rambam's exact language occupies the bulk of the page, rather than the version change. (5)

It should be stated that as a matter of fact, once a person utilizes editions based on quality manuscripts (rather than print editions), the number of significant version changes that are not mere formulations but actually different halachic determinations (such as differences between the first and second edition of Mishneh Torah, marked as מה"ב or מה"ק), are very few. In this edition we have also included comments that are of secondary importance, where the precise language used can lead to differing interpretations. In this way, we achieved an average number of less than one comment per chapter. This book was written for the entire nation of Israel; and it is for this very reason that the present version does not focus on critically presenting all possible text versions, which do not interest the regular reader but only scholars who wish to understand the language adopted by various interpreters, in order to understand the interpretation they gave according to the text version that was before them. Were we to compare our version with the widespread Vilna version, we would have deviated from the focus we set ourselves and the main text would have become secondary to an endless tinkering with the comparison of distorted versions, even if such versions are relevant for the understanding of various commentators.

The version change included an inspection of the Rambam’s Responsa (6) (References have been made to the Blau edition), the Rabbi Avraham son of the Rambam’s Responsa and the Rabbi Y the Nagid’s Responsa, including a reference to the places where our version differs from them. The latter sources were mostly compatible with our main text. We tried to use as few versions change comments as possible, and so not real reason to note them, even though they could have accorded our version even greater validity.

The text was printed using the shorter spelling form (KETIV KHASSER).

The Rambam did not punctuate his composition, but we added partial punctuation for the reader's convenience, comprising only commas and periods besides quotation marks when quoting verses.

All abbreviations have been expanded.

The final letters "MEM" and "NUN” have not been used consistently, thus preserving the same inconsistency of the Rambam's Mishna manuscript.

An asterisk (*) within the main text indicates a reference to the alternative versions given in the margins. The legend of the various alternate text marks, is as follows:
א - Indicates the signed Oxford manuscript (herein singled out because of its importance).
ד - Indicates printed versions (especially as regards the distribution and numbering of the halachot).
י - Indicates the “Yad Peshuta” edition (singled out because of its important commentary).
כ - Indicates other excellent manuscripts (including Rabbi Shilat's edition).
ק - Indicates the Kapakh edition (Rabbi Kapakh's comments regarding version changes).
ש - Indicates a comment by Rabbi Shilat.
מה"ק - Indicates the first edition of Mishneh Torah.
מה"ב - Indicates the second edition of Mishneh Torah.
The + sign in version changes indicates that the proposed version should be added in the place where the asterisk is located. When the + sign does not appear, the existing version is to be replaced with the proposed version (within the body of the context up to the asterisk sign).
The prefix “של” is always flush with the word that it precedes (“שלשבת” = "של שבת") in order to remain faithful to the manuscripts, and the common language usage of the Mishnah and all our primary sages. There are even places, where the separation of the words may have even concealed the definite article preceding the following word (“שלשבת” = "של השבת"). We have seen that one easily gets into the habit of reading the possessive "של" flush with the word that it precedes, and this leads the reader to pay greater attention to the actual language used by the sages, their unique style and their significance, which often differs from our own language.

The Rambam divided his Halachot into short units in order to study them by rote: "And I shall divide each and every chapter into small Halachot, so that they may be ordered by rote" (Introduction, 40). A triangle of dots and a space separated one Halacha from the next. In the printed versions, this division was distorted and other divisions, strangely different was accepted with the first imprintings. Thus, the most widespread print edition, the Vilna Edition, there are hundreds of incorrect divisions of Halachot. Sometimes the segment is to large (i.e., a single item incorporates a number of Halachot) and sometimes a single Halacha is segemented.

In the present edition we have clearly and decisively restored the original division of the Rambam: Every new Halacha in the manuscripts was given a new paragraph. Halachot were divided according to the manuscripts edition of Rabbi Kapakh and according to the distribution of Halachot given by the Frenkel edition, which was also carried out, according to their testimony, according to "manuscripts of the Rambam that came form Yemen and are known to be extremely precise and authoritative, and it is plausible that they changed nothing from the division of Halachot carried out by our Rabbi". (A list of the differences between the division of the Kapakh edition and this edition, will be posted in the Yeshiva's website).

The Rambam did not assign numbers to his Halachot. The extensive numbering of the Halachot was only instituted in the first imprintings. In the present edition, we so no reason to number the Halachot in the manuscripts, not only because there is no single agreed and uniform division in all manuscripts, but especially because double numbering (printed versions and manuscripts) would be very confusing, and there are no references to such numbering in the literature. The numbering of the Halachot was done according to the widespread Vilna edition, which has already become accepted and is extensively referenced in all Torah literature. The reader can get his own impression regarding the excellent and original division of the Halachot and the distortion caused by the old division. (7) The only Halachot we numbered are those in the appendices (the introduction, the text of the Haggadah and the prayer book), which were not numbered in the printed versions and which we numbered according to the distribution of Rabbi Kapakh.

Quoted verses were punctuated according to the text of the Messora, based on the most precise Yemenite manuscripts.

Places written and read differently: Where the ''read version'' differs from the ''written version'', without the diacritics (such as, ''Hoo'' read as ''Hee''; ''LANA’AR'' read as ''LANA’ARA'', etc.), we have copied the ''written'' version as found in the manuscripts and marked it thus: (היא)[ הוא].

Marking of verses: In places where it was written ''etc.'' or ''and so on'', we wrote three dots (...) according to the accepted custom. We have also recorded three dots in places were parts of a verse that is not marked in the manuscript have been skipped. When presenting a sequence of verses, we marked a period (.) at the end of each verse.

Spelling of the Tetragrammaton: G-d's name in the manuscripts has been represented by three Yudim ''ייי'' (8), where the middle Yud is slightly elevated relative to the other two. In order to preserve this spelling, yet avoid an unwieldy text, we spelled G-d’s name with two Yudim.

References: All appearances of Tanakh verses were marked anew (as was already done before us by the ''Mechon Mamre'' edition). In cases where there were more than three cases, we wrote, etc. The Rambam quoted about 4,000 verses from memory; when a verse was noted in a form that differs from the Massora, (9) we used round parentheses to mark the original form found in the manuscripts and square parentheses to indicate the correction, e.g.: ''You will not deviated (from all) [from] the matter'' (Deuteronomy, XVII, 11). In cases were the verse is a ''combined'' creation of a number of verses, we wrote the sources of the verses and added the word ''combined'' (בשילוב).

The drawings were artistically redrawn according to the Kapakh edition. In places where this was possible, such as where the Menorah, the Mizbe'akh and the Heikhal - we took care to maintain a uniform scale (proportional). The scroll-script (סת"ם) sections in the book of Ahava, were rewritten according to the Yemenite tradition (see for example, the curled letter “Feh” in the Song of the Sea).

This edition includes the following indices:

2 indices for the Rambam's books and the Halacha section, in their order, and according to their alphabetic order. These indexes are also presented on the inside cover, thus allowing easy navigation among the 14 books and the various Halachic sections.

Two indices for the 613 commandments, coordinating between the enumeration of the commandments in the structure of the book in the introduction and the short enumeration of the commandments. The index also provides cross-references between the Rambam’s 'book of commandments' and the itemization of the commandments in Mishne Torah.

An index for about two thousand Tanakh verses with the exact phrasing of the verse being quoted and full references to all of their sources in the “Mishneh Torah”. The index is also arranged according to the weekly Series and can provide the Rambam's refreshing explication of verses. The cross-referencing between the various quotations of the verse, and the verse itself, contributes greatly to a comprehensive understanding of the subject. The many quotations of verses from the written Torah within a book which comprises the very essence of the Oral Torah, can provide a strong basis for the connection between the written and oral Torah.

And index of entries and concepts. This index enables the reader to find every Torah entry and subject along with a great many references and sub-entries that arise from the main entry. This index provides a way to perceive various complementary aspects of the Halacha and coordinate between their various manifestations, thus even making it possible to solve difficulties that were found among various commentators who were not aware of the various forms of a number of concepts.

An index of persons. The great book of Halachic determination is full of historical events and persons who make this the book of living Torah.

An index of weights and measures that provides both the principles of measurement and the details of the various measurements, such as area and volume, weights, currencies and time units. The index is located within the book so as to provide easy access for frequent reference to the required measure.

The reader will find a number of introductory words at the head of each index.