Was Mizrachi a flat earther?

I am not sure. The Shevus Yaakov referred to the Mizrachi on vaEtchanan as having this implication. We shall see, perhaps. (Meanwhile, previous posts in this series, on the Vilna Gaon, again on the Vilna Gaon, and on the Shevus Yaakov.)

In Devarim 4:32, in parshat vaEtchanan, the Torah states:

לב כִּי שְׁאַל-נָא לְיָמִים רִאשֹׁנִים אֲשֶׁר-הָיוּ לְפָנֶיךָ, לְמִן-הַיּוֹם אֲשֶׁר בָּרָא אֱלֹהִים אָדָם עַל-הָאָרֶץ, וּלְמִקְצֵה הַשָּׁמַיִם, וְעַד-קְצֵה הַשָּׁמָיִם: הֲנִהְיָה, כַּדָּבָר הַגָּדוֹל הַזֶּה, אוֹ, הֲנִשְׁמַע כָּמֹהוּ.

32 For ask now of the days past, which were before thee, since the day that God created man upon the earth, and from the one end of heaven unto the other, whether there hath been any such thing as this great thing is, or hath been heard like it?

On this pasuk, Rashi writes:

and from the one end of the heavens: And also ask of all the creatures from one end [of the heavens] to the other end. This is its simple meaning, but its midrashic explanation is: [This] teaches [us] about Adam’s height, that it was from the earth to the heavens, and that this is the very same measurement as from one end of the heavens to the other end (San. 38b).

ולמקצה השמים: וגם שאל לכל הברואים אשר מקצה אל קצה זהו פשוטו. ומדרשו מלמד על קומתו של אדם שהיתה מן הארץ עד השמים והוא השיעור עצמו אשר מקצה אל קצה:

Mizrachi, in his commentary on Rashi on vaEtchanan, explains:

and from one end of the heavens: and also ask of all the creatures which are from one end to the other end. {End citation of Rashi.}

He {=Rashi} adds "and also ask" upon "and from one end of the heavens" for without this, one might this that the phrase "and from one end of the heavens" is connected with what was previous to it, "since the day that God created man upon the earth" "and from the end of the heavens until the other end of the heavens," and this is not correct. For "since the day that God created" is referring to the "days past" which refers to the time. But "and from the end of the heavens" does not refer to time but rather to places. And together with the addition {of Rashi} of "and also ask," it is a question all by itself. Also, he {=Rashi} explains "from the ends of the heavens" as "to all the creatures who are from one end to the other end, because the places which are from one end to the other cannot be asked."

{Again quoting Rashi:}

but its midrashic explanation is: [This] teaches [us] about Adam’s height, that it was from the earth to the heavens, and that this is the very same measurement as from one end of the heavens to the other end. {End quote of Rashi.}

In perek Ain Doreshin {Chagiga 12a; also found in Sanhedrin 38b}: R. Eleazar said: The first man reached from earth to heaven, as it is stated {Devarim 4:32},

לב כִּי שְׁאַל-נָא לְיָמִים רִאשֹׁנִים אֲשֶׁר-הָיוּ לְפָנֶיךָ, לְמִן-הַיּוֹם אֲשֶׁר בָּרָא אֱלֹהִים אָדָם עַל-הָאָרֶץ, וּלְמִקְצֵה הַשָּׁמַיִם, וְעַד-קְצֵה הַשָּׁמָיִם: הֲנִהְיָה, כַּדָּבָר הַגָּדוֹל הַזֶּה, אוֹ, הֲנִשְׁמַע כָּמֹהוּ.

32 For ask now of the days past, which were before thee, since the day that God created man upon the earth, and from the one end of heaven unto the other, whether there hath been any such thing as this great thing is, or hath been heard like it?

{where the derasha is that Adam who God created, namely Adam Harishon, was on the earth and to the ends of heaven, thus making him quite tall.}

Rab Judah said in Rab's name: The first man reached from one end of the world to the other {this in terms of width}, as it is stated:

לב כִּי שְׁאַל-נָא לְיָמִים רִאשֹׁנִים אֲשֶׁר-הָיוּ לְפָנֶיךָ, לְמִן-הַיּוֹם אֲשֶׁר בָּרָא אֱלֹהִים אָדָם עַל-הָאָרֶץ, וּלְמִקְצֵה הַשָּׁמַיִם, וְעַד-קְצֵה הַשָּׁמָיִם: הֲנִהְיָה, כַּדָּבָר הַגָּדוֹל הַזֶּה, אוֹ, הֲנִשְׁמַע כָּמֹהוּ.

32 For ask now of the days past, which were before thee, since the day that God created man upon the earth, and from the one end of heaven unto the other, whether there hath been any such thing as this great thing is, or hath been heard like it?

It is a contradiction between one verse and another {actually, one verse and itself, though different parts of the verse}!

{No.} Both this {statement} and that are one measurement. And Rashi comments

"upon the earth and to the ends of heaven" {=Rabbi Eleazar}: this is from the earth until the firmament.

And in another variant text:

"upon the earth and to the ends of heaven" {=Rabbi Eleazar}: he was upon the earth and he reached the heavens.

{and}
"and from the end of heaven until the end of heaven" {=Rav Yehuda citing Rav}: from the end of the world until its {other} end.

"the verses contradict one another": for one says "from the ends of the heavens until the ends of the heavens" which is from one end of the world to the other, and one said "upon the earth and until the end of heaven" which is from the earth until the firmament.

And it teaches that "this and that are a single measure." To explain, the measurement which is from the earth until the firmament is itself

the same measure as from one end of the earth until the other end. For the point on the circumference {=zenith} is one end {of the length of heaven} and the center of heaven, which is the ground, is the other end{see red circle in the middle of the picture}. Not the zenith opposite it, for this would then also be the opper point, just like the other end. {Note: I drew this an an oval rather than a circle, because this appears to be what he is saying, and the only way that the diameter across is equal to the radius from the midpoint to the zenith. Otherwise, the length of the earth would be 2X the length.}

And furthermore, if so {that it was a perfect circle rather than an oval as pictured}, Adam Harishon would not have been able to stand on his legs until after he sinned. For since his stature was from the eastern edge {of the earth} until the western edge {of the earth}, which is twice from the earth until the heavens {since the former is the diameter and the latter is the radius}, it is not possible for him to stand, but only lay prostrate, for then his head would be at the circumference on the east and his legs at the circumference on the west.

And according to this {oval rather than circle picture}, from the land until the firmament is called "upon the earth, and to the edge of heaven" and it is called as well "from the end of the earth until its {other} end." And there is no difference in all of this except in what one calls it. And therefore, the explanation of this Scripture according to its midrash is that Adam was "upon the earth and until the edge of heaven," which is the same as "from the edge of heaven until the edge of heaven." And this is what Rashi wrote, that his stature was from the earth until heaven, and that it was the self-same measure which was from one end to the other.

End quote of Mizrachi. It certainly seems to be in accord with the Shevus Yaakov's understanding, that Mizrachi understands the gemara as referring to a flat earth. Perhaps one can explain it in another way? At any rate, I see that ADDeRabbi discussed Yad Ramah which seems to be saying the same thing as Mizrachi, that according to this gemara the height of the hemisphere is equal to its width, though he rejects this at the end.

If we agree that Mizrachi believed in a flat earth {or at least that Chazal in Chagiga believed in a flat earth, and that Rashi believed the same; and where it then stands to reason that Mizrachi believed it as well}, then it is quite strange. Well, not so strange. We just saw on parshat Devarim that he is perfectly willing to accept Og's thighbone as three parsangs long, despite Rambam's assertion that those who take such midrashim literally are foolish. Not necessarily does he give credence to contemporary scientific findings.

Here, he appears to believe two things. First, the geocentric model of the universe. After all, he is talking about a circular firmament around the earth. This is not so surprising. Rabbi Eliyahu Mizrachi was, after all, born in 1455 and died in 1525 or 1526. Meanwhile, Galileo was born in 1564.

Second, he appears to believe in a flat earth. This is more difficult, given that almost no one back then believed in a flat earth. This was even prior to Magellan and based on Greek science. But indeed, Magellan began his expedition to circumnavigate the globe in 1519 and managed to return to Spain in 1522. This was admittedly towards the very end of Mizrachi's life, though it was first published after his death by his son. But this may have been written before he heard of the feat, or before the feat, or he might have disbelieved it even so.

Why is this important? Maybe it isn't. But perhaps it is, to demonstrate that this was a credible position among Jews at that time, despite contemporary scientific evidence or beliefs.