The Rambam in his introduction to perek Chelek discusses midrashic literalist, and classifies different approaches of different groups to midrash. He writes:
You should know that as to [understanding] the words of the sages [Rambam is referring to Aggadeta] people are divided into three groups. The first group consists of the majority of the people I met, those that I read their books or that I heard about. They understand them literally without explaining them at all, accepting impossibilities as fact [literally: impossibilities as necessary existents]. They did this because of their ignorance [literally: foolishness] and their distance from the sciences, not having enough perfection to take notice themselves or because no one brought this to their attention [that these things are impossible. In other words, the lack of learning and information does not even trigger in their mind the possibility that this is absurd.] They therefore think that all the intelligent sayings of the sages are to be understood literally, as they understand them, although there are some sayings that are strange. Some things they say would stump even the masses and how much more the unique [learned] ones among them. This pathetic [literally: poor] group [literalists], a pity on their foolishness, think that they are elevating [as in bringing respect to] the sages, while they are utterly debasing them without even taking notice. I swear in God’s name [literally: By the life of God], that this group destroy the beauty of the Torah and darken its luster presenting it in a way that is the opposite of what was its intent. God stated about the wisdom of His Torah that “when they hear all these statutes”… while this group understands the words of the sages in a way that if the nations will hear this they will say “this small nation is foolish!”
The midrash about the Sun and Moon being the same size is probably one such midrash which is not intended literally. As msh210 writes in this parallel question, correctly I think,
Presumably this midrash is not meant literally. (Moons don't talk, for one thing.)
The midrash in question appears in Chulin 60b and in Bereishit Rabba:
Rabbi Shimon ben Pazi said: Two verses contradict one another: “And God created the two great luminaries” [Gen 1:16], and it is written, “the great light... and the small light” [ibid.]. The moon said before the Holy One blessed be He: Master of the Universe, can two kings wear one crown? He said to her: Go and diminish yourself. She said before Him: Master of the Universe, because I said a proper thing before You, must I diminish myself?! He said to her: Go and rule over the day and the night. She said to Him: Of what benefit is a candle in bright daylight? Of what benefit can I be? He said: Let Israel count days and years by you. She said to Him: the day is also impossible, nor are tekufot counted according to me. As is written: “and they [i.e., both the sun and the moon] shall be for seasons and appointed times, for days and years” [ibid. 1:15]. [He said:] Go and let the righteous be called by your name—Jacob the Small [Amos 7:5], Samuel the Small [1 Sam 2:19], David the Small [1 Sam 16:11, 17:14].
On a peshat level, the pesukim pose no contradiction. The two great luminaries, Sun and Moon, refer to the fact that they are both large. And the large luminary and small luminary refer to their comparative size. But the midrash makes a derasha.
This midrash has certainly been interpreted allegorically. Thus:
I can only touch very briefly upon another line of interpretation, appearing both in Maharsh”a (R. Shmuel Idels of Ostraha, the most important commentator on the aggadah in the Talmud), and in the previously-mentioned midrash in Genesis Rabbah 6.3: viz. that the moon here symbolizes the Jewish people, whose historical destiny was to assume a “diminished,” politically subjugated role through much of their history. God’s counsel to the moon is also His advice to the Jews: to accept their difficult, “smaller” situation, of having only “reflected“ light in this world (which is compared to night), with a kind of philosophical resignation; and to comfort themselves, (a) with occasional periods of ascent, and (b) with the promise of messianic redemption.
R. Aha b. Hanina also said in the name of R. Assi in R. Johanan's name: Whoever pronounces the benediction over the new moon in its due time welcomes, as it were, the presence of the Shechinah: for one passage states, This month;12 whilst elsewhere it is said, This is my God, and I will giorify Him.13 In the school of Rabbi Ishmael it was taught: Had Israel inherited no other privilege14 than to greet the presence of their Heavenly Father once a month,15 it were sufficient. Abaye said: Therefore16 we must recite it standing. But Meremar and Mar Zutra allowed themselves to be carried on the shoulders17 when they pronounced the blessing. R. Aha said to R. Ashi: In 'the West,' they pronounce the following benediction: 'Blessed be He who reneweth the moons.' Whereupon he retorted: Such a blessing even our women folk pronounce!18 But [one should rather use the following], in accordance with Rab Judah, who gives it thus: Praised etc.19 who created the Heavens with His word, and all their hosts with the breath of His mouth. He appointed unto them fixed laws and times, that they should not change their ordinance. They rejoice and are glad to do the will of their Creator. They work20 truthfully, for their action is truth. The moon He ordered that she should renew herself as a crown of beauty for those whom He sustains from the womb,21 and who will, like it, be renewed in the future, and magnify their Maker in the name of the glory of His kingdom. Blessed art Thou, O Lord, who renewest the moons.
And later, in the post-Talmudic minor tractate Soferim, we find:
אין מברכין על הירח אלא במוצאי שבת, כשהוא מבושם, ובכלים נאים, ותולה עיניו כנגדה, ומיישר את רגליו, ומברך, אשר במאמרו ברא שחקים, וברוח פיו כל צבאם, חוק וזמן נתן להם שלא ישנו את תפקידם, פועלי אמת שפעולתם אמת, וללבנה אמר שתתחדש באור יקר ועטרת תפארת לעמוסי בטן, שהם עתידים להתחדש כמותה, ולפאר ליוצרם על כבוד מלכותו, ברוך אתה י"י מקדש ישראל וראשי חדשים. ואומר שלש פעמים, סימן טוב, סימן טוב, סימן טוב, תיהוי לכל ישראל, ברוך בוראך, ברוך יוצרך, ברוך מקדשך, ורוקד שלש רקידות כנגדה, ואומר שלש פעמים, כשם שאני רוקד כנגדך ואיני נוגע בך, כך אם ירקדו בני אדם כנגדי לא יגעו בי, תפול עליהם אימתה ופחד, ולמפרע, אמן אמן אמן, סלה הללויה. ואומר לחבירו שלש פעמים שלום עליך, וילך לביתו בלב טוב. והדה היא מפסיקין לראשי חדשים.
Neither of these texts mentions such a prayer for restoration of the moon to match the sun or the sun to its even greater light. Nor it is in the Rambam, hilchos Berachos, perek 10. The Arizal added various mizmorim at the end of Kiddush Levana. As Wikipedia states:
It is customary to say additional passages that were added to this blessing in the 16th century by Rabbi Yitzhak Luria. These are Kabbalistic verses and it is difficult to understand their deeper meaning.
My guess (but I have not researched this nearly enough) is that this passage praying for restoration of the moon and sun is one such added passage. This reads as follows:
וִיהִי רָצוֹן מִלְּפָנֶיךָ ה` אֱלֹהַי וֵאלֹהֵי אֲבוֹתַי לְמַלֹּאת פְּגִימַת הַלְּבָנָה וְלֹא יִהְיֶה בָּהּ שׁוּם מִעוּט. וִיהִי אוֹר הַלְּבָנָה כְּאוֹר הַשמש וּכְאוֹר שִׁבְעַת יְמֵי בְרֵאשִׁית כְּמוֹ שֶׁהָיְתָה קוֹדֶם מִעוּטָהּ. שֶׁנֶּאֱמַר אֶת שְׁנֵי הַמְּאֹרוֹת הַגְּדוֹלִים
This seems to have kabbalistic significance, about the primordial light (such that the Or was created before the Sun, and was hidden away for the righteous messianic days) and if so would not (necessarily) be intended literally either.
Yet the idea appears much earlier, as we can note in the direct parallel to both moon and sun in Yeshaya 30:
וְהָיָה אוֹר-הַלְּבָנָה, כְּאוֹר הַחַמָּה, וְאוֹר הַחַמָּה יִהְיֶה שִׁבְעָתַיִם, כְּאוֹר שִׁבְעַת הַיָּמִים--בְּיוֹם, חֲבֹשׁ יְהוָה אֶת-שֶׁבֶר עַמּוֹ, וּמַחַץ מַכָּתוֹ, יִרְפָּא. Moreover the light of the moon shall be as the light of the sun, and the light of the sun shall be sevenfold, as the light of the seven days, in the day that the LORD bindeth up the bruise of His people, and healeth the stroke of their wound.
On the basis of all of this, is there any evidence that this was intended / should be taken literally? Are there any Rishonim or Acharonim who take a stand about the pasuk, about kiddush levana, or about the midrash in Chulin/Bereishit Rabba and say that it is literal?
Note: Inspired by this question, and giving much more in the way of sources, but phrased in a way that would not make it a duplicate.