Mdthbs

The Mishnah in Sotah (3:4) states:

אם יש לה זכות היתה תולה לה יש זכות תולה שנה אחת יש זכות תולה ב' שנים יש זכות תולה ג' שנים מכאן אומר בן עזאי חייב אדם ללמד את בתו תורה שאם תשתה תדע שהזכות תולה לה ר"א אומר כל המלמד בתו תורה לומדה תפלות

IF SHE POSSESSED A MERIT, IT [CAUSES THE WATER] TO SUSPEND ITS EFFECT UPON HER. SOME MERIT SUSPENDS THE EFFECT FOR ONE YEAR, ANOTHER FOR TWO YEARS, AND ANOTHER FOR THREE YEARS. HENCE DECLARED BEN AZZAI, A MAN IS UNDER THE OBLIGATION TO TEACH HIS DAUGHTER TORAH, SO THAT IF SHE HAS TO DRINK [THE WATER OF BITTERNESS], SHE MAY KNOW THAT THE MERIT SUSPENDS ITS EFFECT. R. ELIEZER SAYS: WHOEVER TEACHES HIS DAUGHTER TORAH TEACHES HER OBSCENITY.

(Soncino translation; capitals in original)

In this answer I made the following point:

Here we have a tannaic dispute wherein one tanna asserts that teaching girls Torah is obligatory. He does not specify what forms of Torah he is referring to. The other tanna does not state that teaching girls Torah is forbidden; rather, he states that teaching girls Torah has a negative consequence.

(Emphasis added)

However, when Rambam codifies this law (Hilchot Talmud Torah 1:13) he writes as follows:

ואע"פ שיש לה שכר צוו חכמים שלא ילמד אדם את בתו תורה מפני שרוב הנשים אין דעתם מכוונת להתלמד אלא הן מוציאות דברי תורה לדברי הבאי לפי עניות דעתן אמרו חכמים כל המלמד את בתו תורה כאילו למדה תפלות

Even though she will receive a reward, the Sages commanded that a person should not teach his daughter Torah, because most women cannot concentrate their attention on study, and thus transform the words of Torah into idle matters because of their lack of understanding.

[Thus,] our Sages declared: "Whoever teaches his daughter Torah is like one who teaches her tales and parables."

(Touger translation)

Rambam here explicitly states that the Sages commanded one to not teach his daughter Torah. Yet as I mentioned above, the Mishnah does not actually seem to say that. It just presents the tannaic opinion that there is a negative effect of teaching Torah to women.

How, then, did Rambam extend this to say that the Sages actually issued a command to not teach them?

I am aware that in the parallel passage in the Jerusalem Talmud, an opinion is presented which states that the Torah should be burned rather than given to women, which is somewhat closer to a "command" to not teach them. However, I did not see the standard Rambam commentaries cite the Jerusalem Talmud as Rambam's source for this statement; they cited the version in the Babylonian Talmud which does not say this.¹

So did Rambam have a different version of the text in Sotah that did in fact say that the Sages commanded to not teach women Torah? Did he somehow extrapolate this command from the text that we have, even though it does not appear to say that? Was there some other external source that he was referring to?

It is perhaps noteworthy that he first says that they commanded not to teach women and only then mentions the statement that teaching them is like teaching them tiflut, perhaps implying that these are two separate things.

^{1. The relatively recent commentary Avodat Hamelech by R. Menachem Karakovsky does indeed cite the passage from the Jerusalem Talmud}

The Mishnah in Avos (4:4) says:

רַבִּי לְוִיטָס אִישׁ יַבְנֶה אוֹמֵר, מְאֹד מְאֹד הֱוֵי שְׁפַל רוּחַ, שֶׁתִּקְוַת אֱנוֹשׁ רִמָּה. רַבִּי יוֹחָנָן בֶּן בְּרוֹקָא אוֹמֵר, כָּל הַמְחַלֵּל שֵׁם שָׁמַיִם בַּסֵּתֶר, נִפְרָעִין מִמֶּנּוּ בְגָלוּי. אֶחָד שׁוֹגֵג וְאֶחָד מֵזִיד בְּחִלּוּל הַשֵּׁם:

Rabbi Levitas, a man of Yavneh, says: Be very, very humble in spirit, for the hope of man is worms. Rabbi Yochanan ben Beroka says: Anyone who desecrates the Name of Heaven secretly, they punish him publicly. There is no differentiation between unintentional and intentional when it comes to desecration of the Name (Sefaria Translation).

Rambam (Deos 2:3) writes:

וְיֵשׁ דֵּעוֹת שֶׁאָסוּר לוֹ לָאָדָם לִנְהֹג בָּהֶן בְּבֵינוֹנִית אֶלָּא יִתְרַחֵק מִן הַקָּצֶה הָאֶחָד עַד הַקָּצֶה הָאַחֵר. וְהוּא גֹּבַהּ לֵב. שֶׁאֵין דֶּרֶךְ הַטּוֹבָה שֶׁיִּהְיֶה אָדָם עָנָו בִּלְבַד אֶלָּא שֶׁיִּהְיֶה שְׁפַל רוּחַ וְתִהְיֶה רוּחוֹ נְמוּכָה לִמְאֹד. וּלְפִיכָךְ נֶאֱמַר בְּמשֶׁה רַבֵּנוּ (במדבר יב ג) "עָנָו מְאֹד" וְלֹא נֶאֱמַר עָנָו בִּלְבַד. וּלְפִיכָךְ צִוּוּ חֲכָמִים מְאֹד מְאֹד הֱוֵי שְׁפַל רוּחַ.

As in your case, he uses the words צוו חכמים, where, in fact, in the Mishnah does no at all say commanded. He repeats this for example in Matnos Aniyim 10:18 from Pesachim 112a. Perhaps there are more. Perhaps Rambam is attempting to demonstrate a broader message in his rulings, which I’d have to look into.

The OP left out the third opinion in that Mishnah:

"....Hence Ben Azzai said: a person must teach his daughter Torah, so that if she has to drink [the water of bitterness], she should know that the merit suspends its effect. [and she won't think the waters just didn't work.]

Rabbi Eliezer says: whoever teaches his daughter Torah teaches her promiscuity.

Rabbi Yehoshua says: a woman prefers one kav (of food) and intimacy to nine kav and abstinence...."

It is a general rule that I have seen throughout the Mishnah and Talmud, that if a Mishnah states one opinion, and then quotes another Rabbi who says something else, that second Rabbi is actually arguing against the first opinion in some way.

If that Mishnah then quotes a third Rabbi, then it also stands to reason that he in fact argues on the previous two opinions as well.

In general, we do not say that they all agree or that they are not directly arguing. Rather, usually it is a three way argument.

This is because the Mishnayos are meant to be very brief. So if the Mishnah quotes someone else, it is not usual to take up words to express others who agree. That is a waste of words because we already knew there is such an opinion etc.

So now we have a three way argument between Ben Azzai, R Eliezer, and R Yehoshua. What does each one hold?

Ben Azzai obviously holds that we should actively seek to teach our daughters Torah (sh'baal peh).

R' Yehoshua holds it is not such a good idea to teach a daughter Torah (sh'baal peh). Rashi explains that this is what R' Yehoshua means.

"..It is therefore not good to teach her Torah" - Rashi

So R' Yehoshua is the opinion that holds it is not advised, but still permitted. It is certainly not an obligation. Therefore he argues with Ben Azzai.

So what does R' Eliezer hold?

He must hold against both Ben Azzai and R' Yehoshua. (Otherwise, the Mishnayos would not quote three Rabbis.)

So R' Eliezer's statement which is much more forceful than R' Yehoshua's statement is accepted to mean that R' Eliezer holds it is in fact forbidden to teach Torah (sh'baal peh) to one's daughter.

The Kesef Mishnah on the Rambam that the OP quoted, says that the Rambam is deciding the law in accordance with R' Eliezer.

So when the Rambam says the sages forbade teaching Torah (sh'baal peh) to one's daughter, he meant the group of sages agreeing with and led by R' Eliezer, who the Rambam holds is the decisive and normative Halachah.

I hope this helps. :)

To add on to @Dr. Shmuel's answer. Here are other places where the Rambam uses צוו as advice:

לְפִיכָךְ צִוּוּ חֲכָמִים הָרִאשׁוֹנִים שֶׁיְּהֵא אָדָם שָׁם דֵּעוֹתָיו תָּמִיד וּמְשַׁעֵר אוֹתָם וּמְכַוִּן אוֹתָם בַּדֶּרֶךְ הָאֶמְצָעִית כְּדֵי שֶׁיְּהֵא שָׁלֵם בְּגוּפוֹ.

וְעַל זֶה צִוּוּ חֲכָמִים וְאָמְרוּ כָּל הַמַּרְבֶּה דְּבָרִים מֵבִיא חֵטְא.

צִוּוּ חֲכָמִים בְּדֶרֶךְ אֶרֶץ שֶׁלֹּא יֹאכַל אָדָם בָּשָׂר אֶלָּא לְתֵאָבוֹן.

וְכֵן צִוּוּ חֲכָמִים וְאָמְרוּ (משנה אבות א ד) "וֶהֱוֵי מִתְאַבֵּק בַּעֲפַר רַגְלֵיהֶם וְשׁוֹתֶה בַּצָּמָא אֶת דִּבְרֵיהֶם":

וְכֵן צִוּוּ חֲכָמִים וְאָמְרוּ (משנה אבות א ד) "וֶהֱוֵי מִתְאַבֵּק בַּעֲפַר רַגְלֵיהֶם וְשׁוֹתֶה בַּצָּמָא אֶת דִּבְרֵיהֶם":

שֶׁכָּךְ צִוּוּ חֲכָמִים הַרְחֵק מִשָּׁכֵן רַע

וְכֵן צִוּוּ חֲכָמִים שֶׁיִּהְיֶה אָדָם מְכַבֵּד אֶת אִשְׁתּוֹ יוֹתֵר מִגּוּפוֹ וְאוֹהֲבָהּ כְּגוּפוֹ.

וְכֵן צִוּוּ עַל הָאִשָּׁה שֶׁתִּהְיֶה מְכַבֶּדֶת אֶת בַּעְלָהּ בְּיוֹתֵר מִדַּאי וְיִהְיֶה עָלֶיהָ מוֹרָא מִמֶּנּוּ וְתַעֲשֶׂה כָּל מַעֲשֶׂיהָ עַל פִּיו

here 1, here 2, here 3, here 4, here 5, here 6, here 7, and here 8.