(ב) וַיְדַבֵּ֥ר אֱלֹהִ֖ים אֶל־מֹשֶׁ֑ה וַיֹּ֥אמֶר אֵלָ֖יו אֲנִ֥י יְהֹוָֽה׃ (ג) וָאֵרָ֗א אֶל־אַבְרָהָ֛ם אֶל־יִצְחָ֥ק וְאֶֽל־יַעֲקֹ֖ב בְּאֵ֣ל שַׁדָּ֑י וּשְׁמִ֣י יְהֹוָ֔ה לֹ֥א נוֹדַ֖עְתִּי לָהֶֽם׃ (ד) וְגַ֨ם הֲקִמֹ֤תִי אֶת־בְּרִיתִי֙ אִתָּ֔ם לָתֵ֥ת לָהֶ֖ם אֶת־אֶ֣רֶץ כְּנָ֑עַן אֵ֛ת אֶ֥רֶץ מְגֻרֵיהֶ֖ם אֲשֶׁר־גָּ֥רוּ בָֽהּ׃ (ה) וְגַ֣ם ׀ אֲנִ֣י שָׁמַ֗עְתִּי אֶֽת־נַאֲקַת֙ בְּנֵ֣י יִשְׂרָאֵ֔ל אֲשֶׁ֥ר מִצְרַ֖יִם מַעֲבִדִ֣ים אֹתָ֑ם וָאֶזְכֹּ֖ר אֶת־בְּרִיתִֽי׃ (ו) לָכֵ֞ן אֱמֹ֥ר לִבְנֵֽי־יִשְׂרָאֵל֮ אֲנִ֣י יְהֹוָה֒ וְהוֹצֵאתִ֣י אֶתְכֶ֗ם מִתַּ֙חַת֙ סִבְלֹ֣ת מִצְרַ֔יִם וְהִצַּלְתִּ֥י אֶתְכֶ֖ם מֵעֲבֹדָתָ֑ם וְגָאַלְתִּ֤י אֶתְכֶם֙ בִּזְר֣וֹעַ נְטוּיָ֔ה וּבִשְׁפָטִ֖ים גְּדֹלִֽים׃ (ז) וְלָקַחְתִּ֨י אֶתְכֶ֥ם לִי֙ לְעָ֔ם וְהָיִ֥יתִי לָכֶ֖ם לֵֽאלֹהִ֑ים וִֽידַעְתֶּ֗ם כִּ֣י אֲנִ֤י יְהֹוָה֙ אֱלֹ֣הֵיכֶ֔ם הַמּוֹצִ֣יא אֶתְכֶ֔ם מִתַּ֖חַת סִבְל֥וֹת מִצְרָֽיִם׃ (ח) וְהֵבֵאתִ֤י אֶתְכֶם֙ אֶל־הָאָ֔רֶץ אֲשֶׁ֤ר נָשָׂ֙אתִי֙ אֶת־יָדִ֔י לָתֵ֣ת אֹתָ֔הּ לְאַבְרָהָ֥ם לְיִצְחָ֖ק וּֽלְיַעֲקֹ֑ב וְנָתַתִּ֨י אֹתָ֥הּ לָכֶ֛ם מוֹרָשָׁ֖ה אֲנִ֥י יְהֹוָֽה׃
(2) God spoke to Moses and said to him, “I am יהוה. (3) I appeared to Abraham, Isaac, and Jacob as El Shaddai, but I did not make Myself known to them by My name יהוה. (4) I also established My covenant with them, to give them the land of Canaan, the land in which they lived as sojourners. (5) I have now heard the moaning of the Israelites because the Egyptians are holding them in bondage, and I have remembered My covenant. (6) Say, therefore, to the Israelite people: I am יהוה. I will free you from the labors of the Egyptians and deliver you from their bondage. I will redeem you with an outstretched arm and through extraordinary chastisements. (7) And I will take you to be My people, and I will be your God. And you shall know that I, יהוה, am your God who freed you from the labors of the Egyptians. (8) I will bring you into the land which I swore to give to Abraham, Isaac, and Jacob, and I will give it to you for a possession, I יהוה.”
תָּנוּ רַבָּנַן: רְבִיעִי (חמישי) גּוֹמֵר עָלָיו אֶת הַהַלֵּל, וְאוֹמֵר הַלֵּל הַגָּדוֹל, דִּבְרֵי רַבִּי טַרְפוֹן. וְיֵשׁ אוֹמְרִים: ״ה׳ רוֹעִי לֹא אֶחְסָר״.
The Sages taught in a baraita: With regard to the fourth (fifth) cup, one completes hallel over it and recites the great hallel; this is the statement of Rabbi Tarfon.
חמישי אומר עליו הלל הגדול דברי רבי טרפון...
On the fifth cup [of wine] one recites the great Hallel. This is the opinion of Rabbi Tarfon....
(י) וְאַחַר כָּךְ נוֹטֵל יָדָיו וּמְבָרֵךְ בִּרְכַּת הַמָּזוֹן עַל כּוֹס שְׁלִישִׁי וְשׁוֹתֵהוּ. וְאַחַר כָּךְ מוֹזֵג כּוֹס רְבִיעִי וְגוֹמֵר עָלָיו אֶת הַהַלֵּל. וְאוֹמֵר עָלָיו בִּרְכַּת הַשִּׁיר וְהִיא יְהַלְלוּךָ ה' כָּל מַעֲשֶׂיךָ וְכוּ'. וּמְבָרֵךְ בּוֹרֵא פְּרִי הַגָּפֶן וְאֵינוֹ טוֹעֵם אַחַר כָּךְ כְּלוּם כָּל הַלַּיְלָה חוּץ מִן הַמַּיִם. וְיֵשׁ לוֹ לִמְזֹג כּוֹס חֲמִישִׁי וְלוֹמַר עָלָיו הַלֵּל הַגָּדוֹל מֵ(תהילים קלו-א) "הוֹדוּ לַה' כִּי טוֹב" עַד (תהילים קלז-א) "עַל נַהֲרוֹת בָּבֶל". וְכוֹס זֶה אֵינוֹ חוֹבָה כְּמוֹ אַרְבָּעָה כּוֹסוֹת. וְיֵשׁ לוֹ לִגְמֹר אֶת הַהַלֵּל בְּכָל מָקוֹם שֶׁיִּרְצֶה אַף עַל פִּי שֶׁאֵינוֹ מְקוֹם סְעֵוּדָּה:
(10) And afterwards, he recites the Grace after the Meals over a third cup and drinks it. And afterwards, he mixes (pours) a fourth cup and finishes the Hallel (a set order of praises from the Psalms) over it. And he recites the blessing of song and that is "May all of your creatures praise you, etc." And he recites the blessing, "Who creates the fruit of the vine," and does not taste anything afterwards the whole night, except for water. And he should mix (pour) a fifth cup and say upon it the Great Hallel (Psalms 136), from "Give thanks to the Lord, for God is good" (Psalms 136:1) to "Upon the waters of Babylon" (Psalms 137:1). And this cup is not obligatory like the [other] four cups. And he can finish the Hallel anyplace that he desires, even though he is not in the place of the meal.
Vilna Gaon, 18thC
We have the custom of pouring a fifth cup and calling it the Cup of Elijah the prophet. The reason is that there is a dispute in the Gemara over whether one needs a fifth cup, and the halakhah is not determined. When Elijah comes, the doubt will be clarified. Therefore, based on this doubt, the cup is poured but not drunk, and it is called the Cup of Elijah, for when he comes, all doubts will be clarified, including this doubt.
(ד) מזגו לו כוס שני, וכאן הבן שואל אביו. ואם אין דעת בבן, אביו מלמדו: מה נשתנה הלילה הזה מכל הלילות, שבכל הלילות אנו אוכלין חמץ ומצה, הלילה הזה כלו מצה. שבכל הלילות אנו אוכלין שאר ירקות, הלילה הזה מרור. שבכל הלילות אנו אוכלין בשר צלי שלוק ומבשל, הלילה הזה כלו צלי. שבכל הלילות אנו מטבילין פעם אחת, הלילה הזה שתי פעמים. ולפי דעתו של בן אביו מלמדו. מתחיל בגנות ומסים בשבח, ודורש מארמי אובד אבי (דברים כו, ה), עד שיגמור כל הפרשה כלה.
(4) They pour a second cup [of wine] for him. And here the son questions his father. And if the son has insufficient understanding [to question], his father teaches him [to ask]: Why is this night different from all [other] nights? On all [other] nights, we eat leavened and unleavened bread, [but] on this night, [we eat] only unleavened bread. On all [other] nights, we eat all kinds of vegetables, [but] on this night, [we eat only] bitter herbs. On all [other] nights, we eat meat roasted, stewed or boiled, [but] on this night, [we eat] only roasted [meat]. On all [other] nights, we dip [vegetables] once, [but] on this night, we dip [vegetables] twice. And according to the son's intelligence, his father instructs him. He begins [answering the questions] with [the account of Israel’s] shame and concludes with [Israel’s] glory, and expounds from “My father was a wandering Aramean” until he completes the whole passage.
There are really 5 questions, or 1 header, and 4 sub questions. Why do we call them "Four Questions" when there are really five? Perhaps it’s so that someone will ask about it, thus leading to more questions. The four questions originally functioned as a guide for the child at the table who didn’t know how to ask questions, thus enabling him to fulfill his obligation to ask questions even though he didn’t have any of his own. Eventually, these four questions morphed into a prescribed part of the Passover liturgy. Nonetheless, questioning at the Passover table isn’t limited to the 4/5 questions; the rituals are meant to provoke questions. The rabbis in the Talmud say that during a Passover Seder, someone should pick up and remove the table from the room. This bizarre ritual, the rabbis note, is meant to elicit the children who are no longer at the table to ask: "What’s going on here?" or "Why is this night different than all other nights (Pesachim 115b)?" Why do we have two hand washings in the Haggadah (Urchatz and Rochtzah), the first of which has no blessing, yet the second one does? For the very same reason it seems; to confound participants into inquiry. In other words, we should build in strangeness into the narrative in order to provoke questions. ––Josh Franklin
Who knows four? I know four: four are the mothers, three are the fathers, two are the tablets of the covenant, One is our God in the heavens and the earth. Who knows five? I know five: five are the books of the Torah, four are the mothers, three are the fathers, two are the tablets of the covenant, One is our God in the heavens and the earth.
מַעֲשֶׂה בְּרַבִּי אֱלִיעֶזֶר וְרַבִּי יְהוֹשֻׁעַ וְרַבִּי אֶלְעָזָר בֶּן־עֲזַרְיָה וְרַבִּי עֲקִיבָא וְרַבִּי טַרְפוֹן שֶׁהָיוּ מְסֻבִּין בִּבְנֵי־בְרַק וְהָיוּ מְסַפְּרִים בִּיצִיאַת מִצְרַיִם כָּל־אוֹתוֹ הַלַּיְלָה, עַד שֶׁבָּאוּ תַלְמִידֵיהֶם וְאָמְרוּ לָהֶם רַבּוֹתֵינוּ הִגִּיעַ זְמַן קְרִיאַת שְׁמַע שֶׁל שַׁחֲרִית.
It happened once [on Pesach] that Rabbi Eliezer, Rabbi Yehoshua, Rabbi Elazar ben Azariah, Rabbi Akiva and Rabbi Tarfon were reclining in Bnei Brak and were telling the story of the exodus from Egypt that whole night, until their students came and said to them, "The time of [reciting] the morning Shema has arrived."