Melachim uMilchamot - Chapter 12

These statements and similarly, the opening lines of the following halachah: “There will be no difference between the current age and the Messianic era except [the emancipation] from our subjugation to the [gentile] kingdoms” are the subject of much debate among the commentaries.
The Ra’avad and many other commentaries maintain that Mashiach’s coming will initiate a miraculous era in which the entire nature of the world will change. As the Rambam mentions, many of the Messianic prophecies appear to imply such a phenomenon.
This difference of opinion stems from a debate among the Sages, Berachot 34b: Rabbi Yochanan states: “All the prophets only prophesied regarding the Messianic age. However, the world to come [is described by the verse]: “Never has an eye seen, besides God.” This contradicts [the opinion of] Shmuel who maintains: “There will be no difference between the current age and the Messianic era except [the emancipation] from our subjugation to the [gentile] kingdoms.”
The Rambam follows Shmuel’s opinion. Accordingly, the prophecies that appear to describe miracles must be interpreted as parables or allegories. In contrast, the Ra’avad accepts Rabbi Yochanan’s opinion which interprets the Messianic prophecies simply and thus, maintains that the Messianic age will initiate a new order and nature will give way to miracles.
Several commentaries attempt to resolve the differences between the two. The Radbaz explains that the miraculous order described by the prophets will prevail only in Eretz Yisrael. In the Diaspora, the laws of nature will continue unchanged. [It appears highly unlikely that the Rambam concurs with this opinion. Firstly, his blanket statement, “There will be no difference between the current age and the Messianic era,” does not lend itself to a differentiation between Eretz Yisrael and the Diaspora. Secondly, as mentioned in the commentary to Chapter 11, Halachah 3, the debate between these Sages concerning the nature of the Messianic era is reflected in their conception of Mashiach himself. Since the Rambam does not expect the nature of the world to change in the Messianic age, he could conceive of Bar Kochbah as a potential Mashiach even though he did not work miracles. However, Bar Kochbah lived in Eretz Yisrael. Thus, according to the Radbaz, he should have manifested miraculous powers.]
The Avodat HaKodesh offers a different resolution, explaining that though the world will follow the rules of nature, the nature of the world will return to its state before the Adam committed the sin of the tree of knowledge. That sin effected the totality of creation. When that Eden-like nature is restored, many of the Messianic prophecies which we regard as miracles can be considered as natural phenomena.
The Sheloh (23b) suggests a third opinion. He explains that, according to Shmuel (and thus, the Rambam), there will be two periods in the Messianic age: one in which the natural order of the world will not change and a second period which will be marked by miracles.
The Rambam’s inclusion of the resurrection of the dead as one of the thirteen principles of faith appears to support this opinion. There is no greater miracle and departure from the natural order than that (Likkutei Sichot).
See also lggeret Techiat HaMeitim, Section 6, where the Rambam writes that these words do not represent a definite and final statement. Here he is defining the absolute minimum of what the Messianic era will bring. It is possible that, in fact, the Messianic era will represent a deviation from the natural order.

Prophets would frequently use metaphors and parables to illustrate their messages. Indeed, Numbers 23:7 uses the word meshal, "metaphor," as a synonym for prophetic discourse.

The lamb or the goat.

Generally, this term refers to Judaism (see Hilchot Chagigah 3:1,6). Both Rashi (Avodah Zarah 24a) and the Ran (Derushot, 7) state in the Messianic age, the gentiles will all convert to Judaism. However, the Rambam’s wording does not imply such a change. On the contrary, Halachah 5 differentiates between “the entire world” and “Israel” indicating that even in the Messianic age, differences will exist between Jews and gentiles. Accordingly, certain texts amend this phrase to read “return in repentance.”
The status of the gentiles in the Messianic age is also discussed in Emunot V’De’ot, in the discourse, HaGeulah HaAtidah.

See the commentary to Halachah 1. Indeed, the Yemenite manuscripts and the original printings of the Mishneh Torah include this paragraph as the conclusion of the previous halachah and begin Halachah 2 with the following lines. The themes of the two halachot also appear to tend to such a division.

The king of Magog,

The nation, see Genesis 10:2. Ezekiel, chapters 38 and 39, describe how "Gog will come up against the land of Israel" and how God "will exercise judgement upon him with pestilence and bloodshed."

Perhaps as part of "the wars of God" which, as stated in Chapter 11, Halachah 4, the Messiah will wage.

The verse concludes "before the coming of God's great and awesome day," a reference to the war of Gog and Magog which will make God's power reknown throughout the world.

In his Commentary to the Mishnah, Ediot 8:7, the Rambam writes that Moses conveyed the tradition that before the coming of Mashiach, Elijah would motivate the people to the service of God. However, he will not make any changes in the Torah. Similarly, Chapter 11, Halachah 3, states: “This Torah, its statutes and its laws, are everlasting. We may not add to them or detract from them.”

Pedigree of lineage is an important factor in Jewish law. A person who is descended from a mamzer or servant may not marry a native-born Israelite. These factors are particularly important regarding priests. The Sages consider it as an accepted tradition that many people of blemished lineage have intermingled with the main body of the Jewish people and that, in the Messianic age, all questions concerning lineage will be clarified.

Ediot (ibid.) cites the opinion of certain Sages who maintain that Elijah's contribution will center on establishing the pedigree of lineage among the Jews. The Sages and the Rambam do not accept this view.

Elijah will eradicate the hatred that exists between men. Our Sages explain that the Temple was destroyed because of unwarranted hatred. When hatred, the cause of the exile, ceases, then, the exile itself will come to an end.

Many commentaries support this opinion, explaining that Elijah will motivate the people to Teshuvah, repentance. This service will hasten the redemption for "When Israel repents, she will immediately be redeemed" (Hilchot Teshuvah 7:5).

For the prophecies can be interpreted in a number of ways.

See Sanhderin 97, 98 for different interpretations of the sequence and details of the Messianic era.

In contrast, the essential concept that Mashiach will come and initiate an era where we will observe Torah and mitzvot in a complete manner is counted as one of the Rambam’s thirteen principles of faith.

I.e., the particular details of the Messianic era.

Sanhderin 97b.

The Sages opposed publicizing an appointed time for the Mashiach’s coming, lest he not arrive at that time and many of the common people become disillusioned and abandon Jewish practice (ibid.).
Nevertheless, throughout Jewish history, many great Sages have fixed certain years as appropriate times for Mashiach’s coming. Indeed, the Rambam himself (lggeret Teiman, page 174 of the Mossad HaRav Kook edition), mentions a specific year as the appointed time when the prophetic spirit will return to Israel and the Messianic era will near.
In lggeret Teiman (p. 1 56), the Rambam rationalizes Saadia Gaon‘s fixation of an appointed time for Mashiach’s coming. He explains that the people’s commitment to Torah and mitzvot was at a particularly low point and unless they were promised a specific time for the advent of the Messianic era, they would have lost faith entirely.
The Talmud states “all the appointed times [for Mashiach’s coming] have passed and the matter is dependent on Teshuvah alone.” Nevertheless, according to the Kabbalists, there are certain years, when there is a greater potential for Mashiach to reveal himself. By publicizing those years, the Sages intended to motivate the nation to Teshuvah and thus, hasten Mashiach’s coming.

In this and the previous chapter.

This refers to a later stage of the Messianic redemption, when the exiles have already been gathered. Before then, Mashiach will have waged "the wars of God" and rebuilt the Temple (see Chapter 11, Halachah 3).

As mentioned in Hilchot Teshuvah 9:2, Mashiach's prophetic abilities will approach those of Moses.

Kiddushin 71a offers two interpretations of the word "purify:" a) "smelt" - Just as a smelter extracts pure metal from an ore, Mashiach will clarify the lineage of the tribes. In contrast, in the present age, all the tribes are intermingled and no one can be sure of his origins. b) "remove the blemish" - All families with tainted lineage who have intermingled with the Jewish people as a whole will be accepted. No notice will be made of their previous difficulties. As apparent from the continuation of the halachah, the Rambam accepts both interpretations.

As the verse continues: "He shall purify the sons of Levi...."

The definition of the lineage of the priests and Levites is of greatest importance for their participation is necessary in the Temple services (Kiddushin, ibid.).

Who presume to be priests or Levites.

Nechemiah.

Priests who could not document their pedigree of lineage.

I.e., because of the questions regarding their lineage, they should not consider themselves as priests.

As mentioned in the commentary to Chapter 5, Halachah 2, the urim vitumim were consulted as oracles. Thus, by use of the prophetic spirit, they could determine the priest's lineage. In the Second Temple, the urim vitumim were not endowed with these prophetic powers (Hilclchot Beit HaBechirah 4:1). Hence, Nechemiah told the priests of questionable lineage to wait for the Messian:c redemption when the doubt concerning their lineage could be resolved.

Though the Rambam maintains that Mashiach will divine the people's lineage without using the urim vitumim, their lineage will be established by the prophetic spirit and not by other means.

The knowledge of one's tribal lineage will be important in regard to the division of Eretz Yisrael and other matters. See Ezekiel, Chapters 47 and 48.

Both an illegitimate child and a slave are forbidden to marry nativeborn Israelites.

Mashiach will be able to identify those families whose lineage is tainted. Nevertheless, since those families have already become intermingled with the Jewish people as a whole, no restrictions will be placed upon them (Kiddushin, ibid.).

All the above will be realized in the Messianic era, but this is not why the Sages desired Mashiach's coming.

In contrast to pagan conceptions of Utopia.

As explained in the following Halachah.

In Hilchot Teshuvah, Chapters 8 and 9, the Rambam describes the world to come as man's ultimate reward. He interprets the world to come as a spiritual realm in which the soul will exist independent of the body. (The Ra'avad, the Ramban, and other Sages whose perspective was influenced by the Kabbalah, interpret the world lo come as the period after the resurrection of the dead when the souls and bodies will both rise and live in this physical world.)

Chapter 9, Halachah 2.

The Rambam did not employ this expression simply as a metaphor for abundance. His words also imply that though physical pleasures will be available, we will not crave them. Rather, we will consider them “as dust.” Despite the benefit we derive from them, we will not attach any importance to them.
In Chapter 9 of Hilchot Teshuvah, the Rambam describes the reward received for the observance of Torah and mitzvot in similar, but not entirely parallel terms. The present passage refers to the reward to be received when the world comes to its ultimate state of fulfillment. Thus, the blessings mentioned surpass those described in Hilchot Teshuvah which refers to the reward that can be received at all times, not necessarily in the Messianic age (Likkutei Sichos).

Even gentiles.

In the Hebrew, the Rambam uses two exclusions to emphasize the total lack of involvement with other concerns. At present, even Torah Sages should spend a certain amount of time in business endeavors to earn their livelihood rather than live off charity (Hilchot Talmud Torah 3:8-9). However, in the Messianic age, there will be such abundant good that there will be no need for efforts of this nature (Likkutei Sichot).

I.e., the mystic, transcendent aspects of Torah and God.

The ocean contains a vast host of living beings. However, the waters cover them to the point that their individual existence is no longer perceived. Similarly, in the Messianic age, the world will continue to exist. However, every element of its existence will be permeated by the knowledge of God.
The Mishneh Torah begins “The foundation of all fundamental principles and the pillar of all wisdom is to know that there is a Primary Entity.” Thus, the text begins and ends with the knowledge of God.
At the outset, the Rambam establishes the awareness of God as man’s fundamental goal in existence. By describing the full range of our Torah practice, he gives us the tools to internalize that awareness and spread it throughout the entire world.

These and the following lines were composed by the Rambam, himself. Accordingly, they should be included in the printing of the Mishneh Torah.