Posted on April 6, 2026
By Hazzan Jacob Sandler.
As we near the final days of Pesah, we revisit the miracle of the splitting of the Sea of Reeds. And there’s a famous line just before the Song of the Sea that reads as follows:
וַיַּ֨רְא יִשְׂרָאֵ֜ל אֶת־הַיָּ֣ד הַגְּדֹלָ֗ה אֲשֶׁ֨ר עָשָׂ֤ה ה֙ בְּמִצְרַ֔יִם וַיִּֽירְא֥וּ הָעָ֖ם אֶת־ה וַיַּֽאֲמִ֨ינוּ֙ בַּֽה וּבְמשֶׁ֖ה עַבְדּֽוֹ:
When Israel saw the mighty hand that God had exercised against the Egyptians, the people stood in awe of God; they believed in God and in His servant Moses.
We recite this verse every morning at the end of P’sukei D’Zimra (the preliminary verses of praise), as an intro to “Az Yashir.” But we might also recognize this from our Haggadah. It is quoted in the passage my family refers to as “Rabbinic Calculus.”
This section begins with Rabbi Jose HaGalili supposing that if there were 10 plagues in Egypt there must have been 50 plagues at the Red Sea. Having read the story, I don’t recall any plagues at the Red Sea. But Rabbi Jose uses two verses from the Exodus narrative and a little simple multiplication to prove his claim. We know the 10 plagues are Blood, Frogs, Lice, Swarms, Cattle Disease, Boils, Hail, Locusts, Darkness and the Slaying of the Firstborn. So that much is what the mathematician calls a “given.” According to Exodus 8:15,
וַיֹּאמְר֤וּ הַֽחַרְטֻמִּם֙ אֶל־פַּרְעֹ֔ה אֶצְבַּ֥ע אֱלֹהִ֖ים הִ֑וא
“the magicians said to Pharaoh [regarding the plagues], this is the finger of God!’”
Therefore, 10 plagues (in Egypt) = 1 Finger of God.
And in our verse above, just before the Song of the Sea it says Israel “saw the mighty hand of God…” Rabbi Jose takes as a given that a hand has 5 fingers.
So if 1 Hand = 5 Fingers. And 1 finger = 10 plagues, then 5 (fingers) x 10 (plagues per finger) = 50 plagues at the Red Sea.
If you followed all that, congratulations! You’re doing great. If you want to see it as purely algebraic, it would look like this:
h=5f and f=10p → h=5(10p)=50p
If you’re still confused, you’re in good company! My family used to skip this page of the haggadah every year, until I insisted we understand what was happening.
Enter Rabbi Eliezer and Rabbi Akiva. These two scholars were moved by the logic of Rabbi Jose, and felt that the grandeur of the Exodus was even greater!
They were each reminded of Psalm 78. It’s not one of the psalms quoted in our liturgy so often, but in summary, it calls on each generation to teach the next generation our history from the Exodus, through the wilderness, even through the early history in the land. The psalmist hopes that in learning our history, and recalling God’s wonders, we might be better keepers of the mitzvot than our ancestors, and it ends with a reference to King David being chosen to tend the flock of God – that is, the Jews.
It would be interesting to have the full psalm recited at a Seder, but Rabbis Eliezer and Akiva focus on one line, Ps78:49:
יְשַׁלַּח־בָּ֨ם ׀ חֲר֬וֹן אַפּ֗וֹ עֶבְרָ֣ה וָזַ֣עַם וְצָרָ֑ה מִ֝שְׁלַ֗חַת מַלְאֲכֵ֥י רָעִֽים׃
And [God] inflicted [in] His burning anger
wrath, indignation, trouble,
And sending the messengers of Evil.
The “[in]” is the key! You see, the Hebrew is ambiguous, and these two Rabbis will interpret slightly differently to make their cases as follows.
Rabbi Eliezer says the plagues were “fourfold” because: “[God] inflicted [in] His burning anger
-
Wrath,
-
Indignation,
-
Trouble,
-
And sending the messengers of Evil.
And he goes on to say that the 10 plagues x4 =40 plagues in Egypt. Which, going back to Rabbi Jose’s logic, means at the Red Sea, there were the equivalent of 200 plagues. (4x5x10=200)
h=5f and f=10p → h=5(10p)=50p
Rabbi E: 4f=40p, 4h=5(4f)=5(40p)=200p
But whereas Rabbi Eliezer saw the “burning anger” as modifying the four inflictions, Rabbi Akiva saw the “burning anger” as an infliction of its own.
He read the verse:
“[God] inflicted
-
His burning anger
-
Wrath,
-
Indignation,
-
Trouble,
-
And sending the messengers of Evil.
And so he claims the plagues were “fivefold.”
And using Rabbi Jose’s logic, says:
Rabbi A: 5f=50p, 5h=5(5f)=5(50p)=250p
10 fivefold plagues in Egypt were 50 plagues – represented as the finger of God. And the Hand which has five fingers, therefore 5×50=250 plagues at the Red Sea.
Too much math for Chol HaMoed? Maybe. But I hope that by slowing down and “showing my work” as my math teachers once insisted, this otherwise dense and confusing section of the Haggadah can become meaningful. And if you’re beginning to understand, you’ve earned an extra macaroon at your seder next year!
Happy Passover! Feel free to ask me to explain it again at our delicious festival kiddush lunches! Now that I’ve cracked the code, I’m eager to help everyone demystify the “Rabbinc Calculus” in our haggadah!
P.S. After 3 years of doing a presentation on this using a cartoon poster I drew, one of my guests finally said she understood it, and it was the highlight of my seder!
