אָמַר רַב יְהוּדָה, דְּאָמַר קְרָא: ״אֹרֶךְ הֶחָצֵר מֵאָה בָאַמָּה וְרֹחַב חֲמִשִּׁים בַּחֲמִשִּׁים״. אָמְרָה תּוֹרָה: טוֹל חֲמִשִּׁים, וְסַבֵּב חֲמִשִּׁים.

The Gemara answers: Rav Yehuda said: This is learned from the verse that stated: “The length of the courtyard shall be a hundred cubits, and the breadth fifty by fifty, and the height, five cubits of fine twined linen, and their sockets of brass” (Exodus 27:18). The Torah said: Take a square of fifty cubits by fifty cubits, and surround it with the remaining fifty cubits until they form a square, each side of which measures seventy cubits and a remainder.

for Video Shiur click here to listen:  Psychology of the DAF Eruvin 23 

The idea of 50 x 100 represents a folding of space, and the Gemara itself, does another fold making it 70 and bit by 70 and a bit.  The Midrash understands this and relates several instances where the small area miraculously absorbed the entire people.  The courtyard of the Bais Hamikdash was one such place, where they would be jam packed like a pre-Covid NYC subway car during rush hour, yet when they would bow down, they all had room. 

וַיֹּאמֶר יְהוֹשֻׁעַ בְּזֹאת תֵּדְעוּן כִּי אֵל חַי בְּקִרְבְּכֶם, וְאַף בִּירוּשָׁלַיִם, דִּתְנַן עוֹמְדִים צְפוּפִים וּמִשְׁתַּחֲוִים רְוָחִים. רַבִּי שְׁמוּאֵל בְּרַבִּי חָנָא בְּשֵׁם רַבִּי אַחָא אָמַר, אַרְבַּע אַמּוֹת לְכָל אֶחָד וְאַמָּה מִכָּל צַד, כְּדֵי שֶׁלֹא יְהֵא אָדָם שׁוֹמֵעַ תְּפִלָּתוֹ שֶׁל חֲבֵרוֹ.

When they bowed they had four cubits and one more cubit so they can pray in privacy.

Bereishis Rabbah 5:7

בְּנֹהַג שֶׁבָּעוֹלָם אָדָם מְפַנֶּה כְּלִי מָלֵא בְּתוֹךְ כְּלִי רֵיקָן, שֶׁמָּא כְּלִי מָלֵא בְּתוֹךְ כְּלִי מָלֵא, כָּל הָעוֹלָם כֻּלּוֹ מַיִם בְּמַיִם, וְאַתְּ אוֹמֵר אֶל מָקוֹם אֶחָד, אֶלָּא מִכָּאן שֶׁהֶחֱזִיק מוּעָט אֶת הַמְרֻבֶּה. (וכולהו נמי איתנהו במדרש קהלת ובאגדות דויקרא רבה). וְדִכְוָותֵהּ (במדבר כ, י): וַיַּקְהִלּוּ משֶׁה וְאַהֲרֹן, אָמַר רַבִּי חֲנִינָא כִּמְלוֹא פִי כְבָרָה קְטַנָּה הָיְתָה בָּהּ, וְכָל יִשְׂרָאֵל עוֹמְדִין בָּהּ, אֶלָּא מִכָּאן שֶׁהֶחֱזִיק מוּעָט אֶת הַמְרֻבֶּה. וְדִכְוָותֵהּ (שמות ט, ח): וַיֹּאמֶר ה' אֶל משֶׁה וְאֶל אַהֲרֹן קְחוּ לָכֶם, אָמַר רַב הוּנָא וְכִי חָפְנוֹ שֶׁל משֶׁה הָיְתָה מַחֲזֶקֶת שְׁמוֹנָה קְמָצִים, אֶתְמְהָא. לֹא דָמֵי הַהוּא דְּחָפַן לְהַהוּא דְּקָמַץ, הַהוּא דְּחָפַן תְּרֵי מֵהַהוּא דְּקָמַץ, וּכְתִיב: וּזְרָקוֹ משֶׁה, נִמְצֵאת חָפְנוֹ שֶׁל משֶׁה הָיְתָה מַחְזֶקֶת שְׁמֹנָה קְמָצִים, אֶלָּא מִכָּאן שֶׁהֶחֱזִיק מוּעָט אֶת הַמְרֻבֶּה. וְדִכְוָותֵיהּ אָמַר רַבִּי יוֹסֵי בַּר רַבִּי חֲלַפְתָּא (שמות כז, יח): אֹרֶךְ הֶחָצֵר מֵאָה בָּאַמָּה וְרֹחַב חֲמִשִּׁים בַּחֲמִשִּׁים, וְכָל יִשְׂרָאֵל עוֹמְדִים שָׁם, אֶתְמְהָא, אֶלָּא מִכָּאן שֶׁהֶחֱזִיק מוּעָט אֶת הַמְרֻבֶּה. וְדִכְוָותֵהּ (יהושע ג, ט): וַיֹּאמֶר יְהוֹשֻׁעַ אֶל בְּנֵי יִשְׂרָאֵל גּשׁוּ הֵנָּה וגו', רַב הוּנָא אָמַר זְקָפָן בֵּין שְׁנֵי בַּדֵּי הָאָרוֹן. אָמַר רַבִּי אַחָא בְּרַבִּי חֲנִינָא סְמָכָן בֵּין שְׁנֵי בַּדֵּי הָאָרוֹן. רַבָּנָן אָמְרִין צִמְצְמָן בֵּין שְׁנֵי בַּדֵּי הָאָרוֹן. אָמַר לָהֶן יְהוֹשֻׁעַ מִמַּה שֶּׁהֶחֱזִיקוּ שְׁנֵי בַּדֵּי הָאָרוֹן אֶתְכֶם, אַתֶּם יוֹדְעִים שֶׁשְּׁכִינָתוֹ שֶׁל הַקָּדוֹשׁ בָּרוּךְ הוּא בֵּינֵיכֶם, הֲדָא הוּא דִּכְתִיב (יהושע ג, י): וַיֹּאמֶר יְהוֹשֻׁעַ בְּזֹאת תֵּדְעוּן כִּי אֵל חַי בְּקִרְבְּכֶם, וְאַף בִּירוּשָׁלַיִם, דִּתְנַן עוֹמְדִים צְפוּפִים וּמִשְׁתַּחֲוִים רְוָחִים. רַבִּי שְׁמוּאֵל בְּרַבִּי חָנָא בְּשֵׁם רַבִּי אַחָא אָמַר, אַרְבַּע אַמּוֹת לְכָל אֶחָד וְאַמָּה מִכָּל צַד, כְּדֵי שֶׁלֹא יְהֵא אָדָם שׁוֹמֵעַ תְּפִלָּתוֹ שֶׁל חֲבֵרוֹ. וְאַף לֶעָתִיד לָבוֹא כֵן, שֶׁנֶּאֱמַר (ירמיה ג, יז): בָּעֵת הַהִיא יִקְרְאוּ לִיְרוּשָׁלָיִם כִּסֵּא ה' וְנִקְווּ אֵלֶיהָ כָל הַגּוֹיִם. רַבִּי יוֹחָנָן סָלֵיק לְמִשְׁאַל שְׁלָמֵהּ דְּרַבִּי חֲנִינָא, אַשְׁכְּחֵיהּ דְּיָתִיב וְדָרִישׁ בַּהֲדֵין פָּסוּק: בָּעֵת הַהִיא יִקְרְאוּ לִיְרוּשָׁלָיִם כִּסֵּא ה', אָמַר לוֹ רַבִּי וְכִי מַחֲזֶקֶת הִיא יְרוּשָׁלַיִם כִּסֵּא ה', אֲמַר לֵיהּ הַקָּדוֹשׁ בָּרוּךְ הוּא אָמַר לָהּ הַאֲרִיכִי הַרְחִיבִי קַבְּלִי אֻכְלוּסַּיִךְ, הֲדָא הוּא דִכְתִיב (ישעיה נד, ב): הַרְחִיבִי מְקוֹם אָהֳלֵךְ, לָמָּה (ישעיה נד, ג): כִּי יָמִין וּשְׂמֹאול תִּפְרֹצִי וגו'.

The way of the world is that one pours a full vessel into an empty one. Perhaps you can pour a full vessel into a full vessel?! All the world was water in water and you say “…into one place…” (Genesis 1:9) Rather from here we learn that a little can hold a lot. Similarly - “Moses and Aaron assembled the congregation in front of the rock…” (Numbers 20:10) R’ Chanina said: there was a space the size of the mouth of a small sieve there, and all of Israel stood there? Rather from here we learn that a little can hold a lot. Similarly – “The Lord said to Moses and to Aaron, "Take yourselves handfuls (chofneichem) of furnace soot…” (Exodus 9:8) R’ Huna said: and could Moshe’s handful hold eight handfuls (kamatzim)? That’s strange! Rather from here we learn that a little can hold a lot. There is no comparison between what one takes in a cupped handful (chofan) and what one takes in a closed handful (kamatz). A cupped handful is twice that of a closed and it is written “…and Moses shall cast it heavenward…” (ibid.) therefore Moshe’s cupped hand held eight closed handfuls. Rather from here we learn that a little can hold a lot. Similarly – R’ Yosi bar Chalifta said: “The length of the courtyard shall be one hundred cubits and the width fifty by fifty cubits,” (Exodus 27:18) and all of Israel stood there? That’s strange! Rather from here we learn that a little can hold a lot. Similarly - “And Joshua said to the children of Israel, Come here…” (Joshua 3:9) R’ Huna said: he stood them all up between the two poles of the ark. R’ Acha bar R’ Chanina said: he placed them between the two poles of the ark. The Rabbis said: he shrank them between the two poles of the ark. Yehoshua said to them: from the fact that the two poles of the ark could hold you, you know that Presence of the Holy One is among you. This is what is written “By this you shall know that the living God is in your midst…” (Joshua 3:10) So too regarding Jerusalem it is taught ‘they stood crowded together, but prostrated themselves with plenty of space between them. R’ Shmuel bar R’ Chana said in the name of R’ Acha: each one had four cubits, and a cubit of space to each side so that no one heard the prayer of his fellow. So too it will be in the time to come, as it says “At that time, they will call Jerusalem the Throne of the Lord…” (Jeremiah 3:17) R’ Yochanan went up to visit R’ Chanina, he found him sitting and interpreting this verse ‘At that time, they will call Jerusalem the Throne of the Lord.’ He said to him: oh my teacher, can Jerusalem really hold the throne of the Lord? He replied: The Holy One said to her ‘spread out your length and breadth and receive your population.’ This is what is written “Widen the place of your tent…” (Isaiah 54:2) Why? “For right and left shall you prevail…” (Isaiah 54:3)

Notably, the earth for the Sotah ritual that is mixed with the water must come from the floor of the Temple which is in the center of the Courtyard.

Mishna Sotah 2:2

נוֹטֵל עָפָר מִתַּחְתֶּיהָ וְנוֹתֵן כְּדֵי שֶׁיֵּרָאֶה עַל הַמַּיִם, שֶׁנֶּאֱמַר (במדבר ה) וּמִן הֶעָפָר אֲשֶׁר יִהְיֶה בְּקַרְקַע הַמִּשְׁכָּן יִקַּח הַכֹּהֵן וְנָתַן אֶל הַמָּיִם:

he would take some dust from beneath it which he puts [into the bowl] so that it would be seen on top of the water; as it is said, “And of the dust that is on the floor of the Tabernacle the priest shall take, and put it into the water” (Numbers 5:17).

I wonder if these matters are related.  How so?  The enclosure of the Bais Hamikdash represents Hashem’s home and his boundaries.  Within that, Hashem miraculously allows for the privacy and space of each person who is praying.  The earth of the Sotah represents the physicality, and also represents the Jewish people who are compared to be as numerous as the dust of the earth (Numbers 23:10).  When boundaries and privacy is respected, then there is plenty of space to grow and indeed, if the Sotah is innocent she is blessed with children (Numbers 5:28).  However, lack of respect for boundaries can lead to catastrophe.

Lest some of you think I am making all of this up, and Eruvin is just a halakhic mesechta, with no meaning beyond Hilchos Shabbos and Yom Tov, keep in mind the words of Maaseh Rokeach Seder Moed Maseches Eruvin on this Mishna of Karpef

וכבר כתבתי כל הדינים אינם יוצאים מפשטן אבל מרמזים לדברים גדולים...וה' יאיר עינינו בתורתו. וידעתי גם ידעתי שיש במסכתא זו רזין דרזין אך כבר כתבתי שאין לנו עסק בנסתרות, עד שיבא עני ורוכב על חמור ויתבערו רוח הטומאה מן הארץ ותמלא הארץ דיעה כמים לים מכסים. בבי"א.

“Though no halakha is removed from its plain meaning and intent, however here there are hints at exalted matters...Eruvin contains secrets upon secrets

for Video Shiur click here to listen:  Psychology of the DAF Eruvin 23

Translations Courtesy of Sefaria