Why Four Cups? Temple Beth-El Board of Trustees Meeting, April 5th, 2016
Redemption Pesachim 68b-69a: they correspond to the four expressions of redemption…

(ו) לָכֵ֞ן אֱמֹ֥ר לִבְנֵֽי־יִשְׂרָאֵ֘ל אֲנִ֣י ה' וְהוֹצֵאתִ֣י אֶתְכֶ֗ם מִתַּ֙חַת֙ סִבְלֹ֣ת מִצְרַ֔יִם וְהִצַּלְתִּ֥י אֶתְכֶ֖ם מֵעֲבֹדָתָ֑ם וְגָאַלְתִּ֤י אֶתְכֶם֙ בִּזְר֣וֹעַ נְטוּיָ֔ה וּבִשְׁפָטִ֖ים גְּדֹלִֽים׃ (ז) וְלָקַחְתִּ֨י אֶתְכֶ֥ם לִי֙ לְעָ֔ם וְהָיִ֥יתִי לָכֶ֖ם לֵֽא-לֹהִ֑ים וִֽידַעְתֶּ֗ם כִּ֣י אֲנִ֤י ה' אֱ-לֹ֣הֵיכֶ֔ם הַמּוֹצִ֣יא אֶתְכֶ֔ם מִתַּ֖חַת סִבְל֥וֹת מִצְרָֽיִם׃

(6) Wherefore say unto the children of Israel: I am G-d, and I will bring you out from under the burdens of the Egyptians, and I will deliver you from their bondage, and I will redeem you with an outstretched arm, and with great judgments; (7) and I will take you to Me for a people, and I will be to you a G-d; and you shall know that I am A-donai your G-d, who brought you out from under the burdens of the Egyptians.

Mitzvot

א"ל ארבע כסי תיקנו רבנן דרך חירות כל חד וחד נעביד ביה מצוה:

[Rava said]...Our Sages decreed for us to drink four cups of wine like free men, and they associated each of them with a Mitzvah.

R. Daniel Landes, quoting R. Yitzchak Ze'ev Halevi Soloveitchik (The Gryz)

adapted from My People's Passover Haggadah Vol 1 p. 136

Each of the four cups is an organizing anchor for a different section of the Seder:

  1. first cup: the Kiddush, declaring the holiness of the day (KADESH)
  2. second cup: telling the story (MAGGID)
  3. third cup: the Grace After Meals, Birkat ha Mazon (BAREICH)
  4. fourth cup: singing the Hallel Psalms (HALLEL)

Comfort

Pesachim 68b-69a: And corresponding to them, G-d will serve B'nai Yisrael four cups of comfort.

(ה) ה' מְנָת־חֶלְקִ֥י וְכוֹסִ֑י אַ֝תָּ֗ה תּוֹמִ֥יךְ גּוֹרָלִֽי׃

(5) O G-d, the portion of my inheritance and of my cup, You support my fate.

(ה) תַּעֲרֹ֬ךְ לְפָנַ֨י ׀ שֻׁלְחָ֗ן נֶ֥גֶד צֹרְרָ֑י דִּשַּׁ֖נְתָּ בַשֶּׁ֥מֶן רֹ֝אשִׁ֗י כּוֹסִ֥י רְוָיָֽה׃

(5) You prepare a table before me in the presence of my enemies; You anoint my head with oil; my cup overflows.

(יג) כּוֹס־יְשׁוּע֥וֹת אֶשָּׂ֑א וּבְשֵׁ֖ם ה' אֶקְרָֽא׃

(13) I will lift up the cup of salvations*, And call upon the name of G-d. *"Cos-Yeshuot" : Cup of SalvationS (plural) - so they count this as two deliverances