Why כי עקרה הוא is correct

Summary: and how the Samaritan correction is a correction, rather than original.

Post: In the very beginning of parashat Toledot, we encounter the following variant between the Samaritan text and the Masoretic text:

The text on the left is the Samaritan while the text on the write is the Masoretic text. In terms of el Hashem vs. laHashem, note how changing la to el simplifies the text slightly, given that lamed in the immediately following lenochach ishto. That could well be the reason for change.

But what about the הוא changing to היא? This seems like a clear case where the Samaritan text is correct. After all, the previous word is עקרה, which would indicate a female!

Minchas Shai notes the strangeness of הוא and cites a derasha:

כי עקרה הוא • הוא
כתיב מלמד שהיו שניהם עקורים כדאיתא בסוף פרק הבא
על יבמתו

Thus, that both of them were infertile. This is the derasha from Rabbi Yitzchak in Yevamot daf 64a, though his prooftext is different:

אמר רבי יצחק יצחק אבינו עקור היה שנאמר (בראשית כה, כא) ויעתר יצחק לה' לנכח אשתו על אשתו לא נאמר אלא לנוכח מלמד ששניהם עקורים היו

R. Isaac stated: Our father Isaac was barren; for it is said, And Isaac entreated the Lord opposite²²  his wife.²³  It does not say 'for his wife' but opposite. This teaches that both were barren.²⁴

Thus, it is derived from the word לנכח, rather from the spelling of הוא. But once it is in place, I suppose it forms a nice support.

Is there any reason to suppose the Masoretic text is correct? I would argue that there is strong reason to believe this.

We are used to regularized spelling. but even English was not always this way. It was up to the writer to choose, and even the same writer did not always choose to spell a word the same way.

So too with Hebrew. When vowel letters (vav, yud, heh, aleph) began being used, not for their consonantal sound, but to indicate the presence of a vowel, there was considerable latitude. This is why we occasionally see a krei / ketiv in Bereishit 39:10 of:

kri - קרי	ktiv - כתיב
שִׁילוֺ	שילה

and in 49:11 of:

kri - קרי	ktiv - כתיב
עִירוֹ	עירה

and in 49:12 of:

kri - קרי	ktiv - כתיב
סוּתְוֹ	סותה

and in 39:20 of:

kri - קרי	ktiv - כתיב
אֲסִירֵי	אסורי

It is not that there were multiple pronunciations which are being indicated by the krei and ketiv, but that the heh could stand in to represent that final vowel, or medial vowel. Eventually, which vowel letter stood in for each sound became standardized. But still, in our Masoretic texts, there are a number (11?) of instances in which hi is spelled with the middle vav rather than yud. {Update: I messed it up. As Yeedle writes in the comment section, most are written with the vav, and the number of exceptions are 18; [actually, yaak points out that 11 was right]. I reversed the one which is more and less common. My point, though, stands. I would add that as a commonly occurring word, it increases the likelihood that it would not get its spelling updated.}

The Samaritan scribes, in their effort to simplify and harmonize, would have good cause to fix the spelling to the more apparent, and modern spelling. But, that does not mean that the original was wrong. Indeed, this is a case of lectio difficilior, that the more difficult text is more likely the original.

By the way, as another example in close proximity, see the word goyim, meaning nations (that of Israel and Edom), spelled גיים, which we pronounce, and which the Samaritans spell as גוים. But more on that in a subsequent post.