אַמָּה עַל אַמָּה בְּרוּם שָׁלֹשׁ אַמּוֹת. וְשִׁיעֲרוּ חֲכָמִים שִׁיעוּר מֵי מִקְוֶה אַרְבָּעִים סְאָה.

A cubit, by a cubit, by a height of three cubits. And the Sages measured the measure of the water necessary for a ritual bath at forty se’a .

אָמַר רַב אַשִׁי, אָמַר לִי רָבִין בַּר חִינָּנָא: שׁוּלְחָן שֶׁל מִקְדָּשׁ שֶׁל פְּרָקִים הֲוָה. דְּאִי סָלְקָא דַּעְתָּךְ הַדוֹקֵי הֲוָה מִיהֲדַק – אַמְּתָא בְּאַמְּתָא הֵיכִי מַטְבְּלֵיהּ?

The Gemara cites a discussion related to the topic of measurements. Rav Ashi said: Ravin bar Ḥinnana said to me: The table of the Temple, upon which the shewbread was placed, was comprised of assembled parts. For if it should enter your mind that the table was firmly connected and could not be taken apart, how could the priests immerse a cubit in a cubit? The dimensions of the table were two cubits by one cubit, with a height of one and a half cubits. If the table contracted ritual impurity, it had to be immersed in a ritual bath. If a ritual bath contains an area of one cubit by one cubit, the table can fit inside only if it is dismantled.

מַאי קוּשְׁיָא? דִּילְמָא בַּיָּם שֶּׁעָשָׂה שְׁלֹמֹה הֲוָה מַטְבִּיל לֵיהּ? דְּתָנֵי רַבִּי חִיָּיא: יָם שֶּׁעָשָׂה שְׁלֹמֹה מַחֲזִיק מְאָה וַחֲמִשִּׁים מִקְוֵה טָהֳרָה.

The Gemara responds: What is the difficulty? Perhaps the priest would immerse it in the sea that King Solomon built, which was a very wide ritual bath, as it states: “And he made the molten sea of ten cubits from brim to brim, round in compass” (I Kings 7:23). As Rabbi Ḥiyya taught: The sea that Solomon built contained the volume of water of one hundred and fifty ritual purification baths. It was certainly possible to immerse even large vessels in this sea.

״וְלֹא יִפְחֲתוּ לוֹ מֵאַרְבָּעָה״. הֵיכִי מְתַקְּנִי רַבָּנַן מִידֵי דְּאָתֵי בָּהּ לִידֵי סַכָּנָה? וְהָתַנְיָא: לֹא יֹאכַל אָדָם תְּרֵי, וְלֹא יִשְׁתֶּה תְּרֵי, וְלֹא יְקַנֵּחַ תְּרֵי, וְלֹא יַעֲשֶׂה צְרָכָיו תְּרֵי!

We learned in the mishna that even with regard to the poorest of Jews, the charity distributors should not give him less than four cups of wine. The Gemara asks: How could the Sages establish a matter through which one will come to expose himself to danger? But wasn’t it taught in a baraita : A person should not eat pairs, i.e., an even number of food items; and he should not drink pairs of cups; and he should not wipe himself with pairs; and he should not attend to his sexual needs in pairs. The concern was that one who uses pairs exposes himself to sorcery or demons. Why would the Sages require one to drink an even number of cups and thereby place himself in a position of danger?

אָמַר רַב נַחְמָן: אָמַר קְרָא: ״לֵיל שִׁמוּּרִים״ – לֵיל הַמְשׁוּמָּר וּבָא מִן הַמַּזִּיקִין.

Rav Naḥman said that the verse said: “It was a night of watching to the Lord” (Exodus 12:42), which indicates that Passover night is a night that remains guarded from demons and harmful spirits of all kinds. Therefore, there is no cause for concern about this form of danger on this particular night.

רָבָא אָמַר: כּוֹס שֶׁל בְּרָכָה מִצְטָרֵף לְטוֹבָה, וְאֵינוֹ מִצְטָרֵף לְרָעָה. רָבִינָא אָמַר: אַרְבָּעָה כָּסֵי תַּקִּינוּ רַבָּנַן דֶּרֶךְ חֵירוּת, כָּל חַד וְחַד

Rava said a different answer: The cup of blessing for Grace after Meals on Passover night is used in the performance of an additional mitzva and is not simply an expression of freedom. Therefore, it combines with the other cups for the good, i.e., to fulfill the mitzva to drink four cups, and it does not combine for the bad. With regard to the danger of drinking pairs of cups, it is as though one drinks only three cups. Ravina said: The Sages instituted four separate cups, each of which is consumed in a manner that demonstrates freedom. Therefore, each and every one