Did Hashem finish Creation on the sixth or the seventh?

Chazal noted the anomaly in Hashem finishing Creation on the seventh day, when there was no described work performed on that day. As Rashi writes, channeling Bereishit Rabba:

And God completed on the seventh day His work that He did, and He abstained on the seventh day from all His work that He did.		ב. וַיְכַל אֱלֹהִים בַּיּוֹם הַשְּׁבִיעִי מְלַאכְתּוֹ אֲשֶׁר עָשָׂה וַיִּשְׁבֹּת בַּיּוֹם הַשְּׁבִיעִי מִכָּל מְלַאכְתּוֹ אֲשֶׁר עָשָׂה:
And God completed on the seventh day: Rabbi Shimon said: [A human being of] flesh and blood, who cannot [exactly] know his times and his moments, must add from the profane to the holy [i.e., he must add some time to the Sabbath.] The Holy One, blessed be He, Who knows His times and His moments [exactly], entered it [the Sabbath] within a hairbreadth, and it therefore appeared as if He completed it [His work] on that day. Another explanation: What was the world lacking? Rest. The Sabbath came, and so came rest. The work was completed and finished. — [from Gen. Rabbah 10:9]		ויכל אלהים ביום השביעי: רבי שמעון אומר בשר ודם שאינו יודע עתיו ורגעיו צריך להוסיף מחול על הקודש, הקב"ה שיודע עתיו ורגעיו נכנס בו כחוט השערה ונראה כאלו כלה בו ביום. דבר אחר מה היה העולם חסר, מנוחה, באת שבת באת מנוחה, כלתה ונגמרה המלאכה:

That is a midrashic take on the textual anomaly. A peshat explanation might be something along the lines of that the work, and the world, was declared finished on that day, since there was no more to be created on that day. (This is something like Rashi's second explanation.) Or it is a pluperfect, or past perfect, that it had been completed. (Simple perfect: he walked. Pluperfect: he had walked.) Or else וַיְכַל has some alternate sense of stoppage.

In Vetus Testamentum, we find that the Samaritans have an interesting variant text for Bereishit 2:2. The Masoretic text is on the right, and differences in the Samaritan text are on the left:

Thus, the Samaritans state that Elokim finished on the sixth day the work that he did, and rested on the seventh day.

The same appears in the Septuagint:

2 καὶ συνετέλεσεν ὁ θεὸς ἐν τῇ ἡμέρᾳ τῇ ἕκτῃ τὰ ἔργα αὐτοῦ, ἃ ἐποίησεν, καὶ κατέπαυσεν τῇ ἡμέρᾳ τῇ ἑβδόμῃ ἀπὸ πάντων τῶν ἔργων αὐτοῦ, ὧν ἐποίησεν.

2 And God finished on the sixth day his works which he made, and he ceased on the seventh day from all his works which he made. 

In the sectarian work, the pseudepigraphic Book of Jubilees, 2:16, we see a similar idea expressed:

16. And He finished all his work on the sixth day - all that is in the heavens and on the earth, and in the seas and in the abysses, and in the light and in the darkness, and in everything.

[Update: HT AryehS.

Also, the Peshitta, a Syriac translation, has the sixth day:

]

However, we should treat this variant with caution, because it is just too perfect. Rabbi Shmuel David Luzzatto (Shadal), in his commentary on this verse, schools us in the idea of lectio difficilior, the rule of the more difficult word being the more likely original, particularly as it pertains to the Samaritan text. (The idea, as I would explain it, is that if a word choice is in truth justifiable, but it seems difficult to the average reader, then that is the more likely original reading, because a scribe will illegitimately emend the text towards the easier reading. When and where to apply this rule requires a careful, judicious approach.)

Shadal writes:

"וַיְכַל אֱלֹהִים -- This is connected with the end of the pasuk -- since on the seventh day all His work had already finished (kila), therefore He rested on the seventh day.

And behold, וַיְכַל is a past tense verb that was already completed [=pluperfect, see above], and there are many like it.

And in the Targum attributed to the 70 [Jewish] elders [the Septuagint], and so too in the sefer Torah of the Cutheans [Samaritans] it is written 'on the sixth day'.  And Clericus already saw that this is nothing but an emendation and a scribal 'fixing', and this is as they said in the Talmud (Megillah 9a) [regarding the idea that the 70 elders made 'fixes' to the text so that the non-Jewish reader would not get confused]. For behold, if it was such that it was written initially 'and God [had] completed on the sixth day', there is no reason it would enter a person's mind to emend [the text to read] ויכל בשביעי. And conversely, if it was initially written בשביעי, it it quite understandable that this language would be difficult to the masses, and they [the authors of Septuagint, and perhaps he intends Samaritans as well] arose and emended it to בששי. And this is an important principle about the matter of variants which are found in the book of the Cutheans [Samaritans], that all the emendations which their scholars emended was due to the smallness and lightness of their understanding and thoughts. And this is as the scholar [Wilhelm] Gesenius explained, with good discernment and knowledge, in his book De Pentateuchi Samaritani origine et indole et auctoritate, Halae 1815. Also the scholar [Johannes Bernardus / Giovanni Battista de Rossi] De-Rossi, though at times is seduced towards the Samaritan nusach, and he doesn't understand all that Gesenius understood, still already wrote, as a general matter, like these words, saying:

Quaelibet lingua et aetas suas habet anomalias et enallages; nec omnes nec semper grammatice scripserunt sacri auctores. Unde non temere rejicienda lectio anomala. Immo anomala lectio plerumque verior. Facillimum namque est anomalis analoga a scribis substitui, analogis anamola difficillimum (Variae lectiones, Vol I. Proleg. par II, §§ 38, 39).

[Josh: My rough translation:] Every age has its own language and anomalies and alteration; nor are all nor is it always the scholar who wrote, of the sacred authors. Hence one should not rashly reject an anomalous reading. Indeed, the anomalous choice is generally truer. It is very easy for scribes to replace an anomalous reading [with an easier one], but substituting an anomalous reading is more difficult."

End quote from Shadal.

(The page from De Rossi's work, Variae Lectiones Veteris Testamenti: Ex Immensa Mss. Editorumque, here:

)

I will, however, present a counterargument. It is true that, as a matter of deliberate scribal emendation, because the scribe (falsely) believed there was an error in the text in need of correction, or because the scribe saw his role as "improving" the clarity of the text, this application of lectio difficilior makes sense.

However, we might also consider the possibility of accidental scribal emendation. Recall that השישי and השביעי begin with the same two letters, הש. So if we were to posit that הששי were original, a scribe might have been copying ביום הששי and lost track after writing ביום הש. Then, "dittography" comes into play. This is the accidental repetition of a letter, syllable, word, or phrase. Realize that ביום השביעי occurs legitimately two times following, first at the end of this pasuk, וַיִּשְׁבֹּת בַּיּוֹם הַשְּׁבִיעִי, and next, without the leading ב in the next pasuk, וַיְבָרֶךְ אֱלֹהִים אֶת יוֹם הַשְּׁבִיעִי. If so, perhaps the scribe accidentally duplicated ביום השביעי here, and that error served as the basis for our masoretic text. (Though note one could argue in the opposite direction, that this is dittography due to יום הששי of the two pesukim earlier.)

Despite this vector of accidental scribal emendation, the fact that the Samaritan text has it makes me strongly suspect that this is a deliberate scribal emendation to make the text read more cleanly. This is indeed characteristic of the Samaritan text. And then, just as we see some midrashim relying on the "easier" Samaritan text of certain pesukim, presumably spread in vulgar (non-checked) texts, this Hebrew version of the pasuk stood as the basis for the Greek translation in the Septuagint.

[Update: Regarding the Peshitta, here is what Rabbi Chaim Heller has to say:

"Footnote 1) See what I wrote in this in my essay on the Targum Yerushlami on the Torah (page 13). Yet it is quite possible that the basis of this variant came about via error, that the copying scribe erred and switched the word השביעי with the word הששי which was written above, close by, and he copied it here. See the introduction, note 3. " 

In that introduction, note 3, where he discusses transcription error and transferring text from related matters close by.

In his sefer, Al HaTargum Hayerushalmi LaTorah, Rabbi Heller writes as follows:

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