Some time ago, while writing a research paper, I was reading the LXX of Psa. 24:1.
The Hebrew text states,
א לְדָוִד מִזְמוֹר ליהוה הָאָרֶץ וּמְלוֹאָהּ תֵּבֵל וְיֹשְׁבֵי בָהּ
which may be translated into English as,
1 David’s psalm. The earth and its fullness are Yahveh’s, the world and all who dwell in it.
But, when I reviewed the LXX, I noticed the inclusion of additional text not found in the Masoretic text.
Αʹ ψαλμὸς τῷ Δαυιδ τῆς μιᾶς σαββάτων τοῦ κυρίου ἡ γῆ καὶ τὸ πλήρωμα αὐτῆς ἡ οἰκουμένη καὶ πάντες οἱ κατοικοῦντες ἐν αὐτῇ
which may be translated into English as,
1 David’s psalm of the first day of the week. The earth and its fullness are Yahveh’s, the world and all those who dwell in it.
In my research, I also had to examine the Talmud, which is part of Jewish law, or halakha. In the Talmud,1 I came across a most interesting passage.
The following are the psalms that were sung in the Temple. On the first day (ביום הראשון), they used to say (Ps. 24:1), “The earth is Yahveh’s, and its fullness, the world, and those who dwell in it.” On the second day (בשני), they used to say (Ps. 48:1), “Great is Yahveh and highly to be praised, in the city of our God, His holy mountain.” On the third day (בשלישי), they used to say (Ps. 82:1), “God stands in the congregation of God; He judges in the midst of the judges.” On the fourth day (ברביעי), they used to say (Ps. 94:1), “O Yahveh, God, to whom vengeance belongs, God, to whom vengeance belongs, shine forth.” On the fifth day (בחמישי), they used to say (Ps. 81:2), “Sing aloud unto God our strength, shout unto the God of Jacob.” On the sixth day (בשישי), they used to say (Ps. 93:1), “Yahveh reigns, He is clothed in majesty; Yahveh is clothed, He has girded himself with strength.” On Shabbat (בשבת), they used to say (Ps. 92:1), “A psalm, a song for the day of the Shabbat.” A psalm for the time to come, for the day that will be all Shabbat and rest for everlasting life.
השיר שהיו הלויים אומרין בבית המקדש: ביום הראשון, היו אומרין "לה', הארץ ומלואה" (תהילים כד,א). בשני, היו אומרין "גדול ה' ומהולל, מאוד" (תהילים מח,ב). בשלישי, היו אומרין "אלוהים, ניצב בעדת אל" (תהילים פב,א). ברביעי, היו אומרין "אל נקמות, ה'" (תהילים צד,א). בחמישי, היו אומרין "הרנינו, לאלוהים עוזנו" (תהילים פא,ב). בשישי, היו אומרין "ה' מלך, גאות לבש" (תהילים צג,א). בשבת, היו אומרין "מזמור שיר, ליום השבת" (תהילים צב,א)--מזמור שיר לעתיד לבוא, לעולם שכולו שבת מנוחה לחיי העולמים
Based on the passage from the Talmud, I concluded that the Jews had a relatively defined liturgy, singing a particular psalm on a particular day of the week. On Sunday, or the first day of the week, they would sing Psa. 24:1.
Question: What does the inclusion of «τῆς μιᾶς σαββάτων» in the LXX of Psa. 24:1 demonstrate about the religious identity of those who translated Psa. 24:1 into the LXX?
The reason I ask is because some Jews (could actually be a majority) assert that only the Torah was translated into Greek by the 70-72 men during the reign of Ptolemy and they disavow knowledge of who translated the remainder of the Tanakh. Consequently, they can reject such passages as the LXX of Isa. 7:14, and so forth. Some even go as far as saying that Christians may have translated some portions of the rest of the Tanakh into Greek.
(Note: I also found δευτέρᾳ σαββάτου in Psa. 48:1, as well as τετράδι σαββάτων in Psa. 94:1.)
Footnotes
1 Babylonian Talmud, Seder Kodashim, Tractate Tamid, Mishna, Chapter 7.4; also, Sefer Moʿed, Tractate Rosh ha-Shana, Gemara, Folio 31a