70 souls? But there are only 69?!

If you count 'em up. And yet, the pasuk states:

כז וּבְנֵי יוֹסֵף אֲשֶׁר-יֻלַּד-לוֹ בְמִצְרַיִם, נֶפֶשׁ שְׁנָיִם: כָּל-הַנֶּפֶשׁ לְבֵית-יַעֲקֹב הַבָּאָה מִצְרַיְמָה, שִׁבְעִים. {ס}

27 And the sons of Joseph, who were born to him in Egypt, were two souls; all the souls of the house of Jacob, that came into Egypt, were threescore and ten. {S}

There are two classic answers. The first (see e.g. Rashi, Ramban with a bit of relaxing, that it was in Egypt) is that Yocheved was born between the walls. This is difficult, because she still was not listed; and the timing would need to be quite precise; and she would need to be 130 when she had Moshe. (Besides that I argue elsewhere that Yocheved was not actually a daughter of Levi, but rather a daughter from the tribe of Levi -- yes, there are difficulties, which I address.)

A second, better answer (see e.g. Rashbam, Ibn Ezra) is that Yaakov is counted, for this is the sum of the house of Yaakov. But it is still slightly awkward.

But I saw a great suggestion in the commentary of Aharon ben Yosef the Karaite, this week. Namely, that the Biblical style is occasionally to prefer whole, round numbers. He tells us to look in Shofetim perek 9, where there is also a case of 69 who are counted as 70, and where missing one person from the number does not matter.

Looking in the previous perek for setup, we have:

ל וּלְגִדְעוֹן, הָיוּ שִׁבְעִים בָּנִים, יֹצְאֵי, יְרֵכוֹ: כִּי-נָשִׁים רַבּוֹת, הָיוּ לוֹ.	30 And Gideon had threescore and ten sons of his body begotten; for he had many wives.
לא וּפִילַגְשׁוֹ אֲשֶׁר בִּשְׁכֶם, יָלְדָה-לּוֹ גַם-הִיא בֵּן; וַיָּשֶׂם אֶת-שְׁמוֹ, אֲבִימֶלֶךְ.	31 And his concubine that was in Shechem, she also bore him a son, and he called his name Abimelech.

Was Avimelech a 71st son? It is unclear. But turning to the 9th perek now. Recall that Yerubaal is the same as Gideon:

א וַיֵּלֶךְ אֲבִימֶלֶךְ בֶּן-יְרֻבַּעַל שְׁכֶמָה, אֶל-אֲחֵי אִמּוֹ; וַיְדַבֵּר אֲלֵיהֶם, וְאֶל-כָּל-מִשְׁפַּחַת בֵּית-אֲבִי אִמּוֹ לֵאמֹר.	1 And Abimelech the son of Jerubbaal went to Shechem unto his mother's brethren, and spoke with them, and with all the family of the house of his mother's father, saying:
ב דַּבְּרוּ-נָא בְּאָזְנֵי כָל-בַּעֲלֵי שְׁכֶם, מַה-טּוֹב לָכֶם--הַמְשֹׁל בָּכֶם שִׁבְעִים אִישׁ כֹּל בְּנֵי יְרֻבַּעַל, אִם-מְשֹׁל בָּכֶם אִישׁ אֶחָד; וּזְכַרְתֶּם, כִּי-עַצְמְכֶם וּבְשַׂרְכֶם אָנִי.	2 'Speak, I pray you, in the ears of all the men of Shechem: Which is better for you, that all the sons of Jerubbaal, who are threescore and ten persons, rule over you, or that one rule over you? remember also that I am your bone and your flesh.'
ג וַיְדַבְּרוּ אֲחֵי-אִמּוֹ עָלָיו, בְּאָזְנֵי כָּל-בַּעֲלֵי שְׁכֶם, אֵת כָּל-הַדְּבָרִים, הָאֵלֶּה; וַיֵּט לִבָּם אַחֲרֵי אֲבִימֶלֶךְ, כִּי אָמְרוּ אָחִינוּ הוּא.	3 And his mother's brethren spoke of him in the ears of all the men of Shechem all these words; and their hearts inclined to follow Abimelech; for they said: 'He is our brother.'
ד וַיִּתְּנוּ-לוֹ שִׁבְעִים כֶּסֶף, מִבֵּית בַּעַל בְּרִית; וַיִּשְׂכֹּר בָּהֶם אֲבִימֶלֶךְ, אֲנָשִׁים רֵיקִים וּפֹחֲזִים, וַיֵּלְכוּ, אַחֲרָיו.	4 And they gave him threescore and ten pieces of silver out of the house of Baal-berith, wherewith Abimelech hired vain and light fellows, who followed him.
ה וַיָּבֹא בֵית-אָבִיו, עָפְרָתָה, וַיַּהֲרֹג אֶת-אֶחָיו בְּנֵי-יְרֻבַּעַל שִׁבְעִים אִישׁ, עַל-אֶבֶן אֶחָת; וַיִּוָּתֵר יוֹתָם בֶּן-יְרֻבַּעַל, הַקָּטֹן--כִּי נֶחְבָּא. {ס}	5 And he went unto his father's house at Ophrah, and slew his brethren the sons of Jerubbaal, being threescore and ten persons, upon one stone; but Jotham the youngest son of Jerubbaal was left; for he hid himself. {S}

So he slew 70 of his brothers, but one was left, namely the youngest one, Yotam.

But we just said that there were a total of 70! The answer is that he actually slew only 69.

And it is not just Aharon ben Yosef the Karaite who says this. We have the much earlier Radak who says the same thing, and draws exactly the same connection between these verses. Pictured to the right is a clip from a beautiful Tanach with Neviim Rishonim, which features the commentaries of Radak and Ralbag on the side. It takes a while to get used to the ornate lettering, but Radak basically says ושבעים חסר אחד הרג. And even though it says 70, this is the minhag halashon in certain places to not to reduce the sum total because of one, such as -- and here is the reference to Vayigash -- that all the souls who came down to Egypt were seventy. Another example he gives is the forty lashes, for which we have a tradition that it is really a maximum of 40 - 1.

So this is actually a third classic answer, found in the work of a classic Jewish commentator, though we need to look non-locally.

Update: Another point to consider is that perhaps 70 is a "magic number" of sorts, like 40. Perhaps the reason taking one or two out from 70 leaves us with 70 there is that there were never really 70, but just a whole bunch of sons.