SHIR SHEL YOM
The last Mishna in Tamid (7:4) enumerates the psalms which the Levites would recite each day in the Beit Ha-mikdash (Temple), after offering the tamid shel shachar. The tamid was a lamb offered twice daily in the Temple (Bamidbar 28:4), in the morning (shachar) and afternoon (bein ha-arbayim). The Gemara (Rosh Ha-shana 31a) explains why each chapter was chosen to be recited on each specific day.
On Monday, Gadol Adonai u’mehulal me’od (גדול יהוה ומהלל מאד, “Great is God and much praised”) is recited, in reference to the second day of Creation, on which He separated the things that he made (the heavens from the earth) and reigned over them.
On Wednesday, El nikamot Adonai (אל נקמות יהוה, “Hashem is a God of vengeance”) is recited, in reference to the fourth day of Creation, on which He created the sun and the moon and how he will ultimately exact punishment from those who worship them. Ends with Lechu Neranana – shabbos The Ari z”l introduced the idea of adding the first three pesukim of Tehillim 95 in order not to end the Shir shel yom with punishment “the L-rd our G-d will destroy them”. A similar idea is seen at the end of Eicha, Lamentations. An additional reason comes from Chassidic teachings. One needs to make spiritual and physical preparations for Shabbos from Wednesday. For this reason, we add these three pesukim which are said in the service of Kabbolas Shabbos
On Thursday, Harninu leilohim uzeinu (הרנינו לאלוהים עוזנו, “Sing joyously to the God of our might”) is recited, in reference to the fifth day of Creation, on which He created the birds and the fish to give praise to his name.
On Friday, Adonai malach gei’ut laveish (יהוה מלך גאות לבש, “Hashem has reigned, he had donned grandeur”) is recited, in reference to the sixth day of Creation, on which He completed his work and reigned over his creations.
On the Sabbath, Mizmor shir leyom haShabbat (מזמור שיר ליום השבת, “A song, a hymn for the Sabbath day”) is recited, in reference to the seventh day of Creation, which is a day that is entirely Sabbath.
The earliest record of specific psalms being identified with certain days may be found in the Book of Tehillim itself, as 92:1 introduces the psalm as a “song for the Sabbath day.”
Furthermore, the Septuagint, the Greek translation of the Bible by seventy-two Jewish elders (Megilla9a-b), introduces certain psalms with the day upon which they were recited by the Levites in the Beit Ha-mikdash.
While originally only the Levites sang Shir shel Yom as the korban tamid was offered, Massekhet Soferim (18:2), after citing the source from Tamid, adds, “one who mentions the verse in its proper time is considered as if he has built a new altar and brought a sacrifice upon it.”
Furthermore, the Machzor Vitry (pg. 712) cites the Talmud Yerushalmi (Ta’anit4:5), which questions whether Shir shel Yom may be recited “without libations,” i.e., outside the sacrificial service, concluding that one may do so. We preface each psalm as that which “the Levites used to say in the Beit Ha-mikdash.“
The Rambam, in his Nussach Ha-tefilla, found at the end of Sefer Ahava, writes that SOME are accustomed to recite Shir shel Yom. However, the Siddur of Rav Amram Gaon simply instructs that one should recite Shir shel Yom.
There are different customs regarding the recitation of Shir shel Yom. According to the Ashkenazic custom (Rema OC 123:2), Shir shel Yom is recited AFTER Aleinu. According the Sephardic custom, one recites Shir shel Yom immediately following the Kaddish of “U-va le-Tziyyon,” and only afterwards does one recite Aleinu.
As Shir shel Yom corresponds to the song recited with the tamid shel shachar, one might question why we do not recite it at Mincha as well, as the tamid shel bein ha-arbayim, which Mincha reflects, was offered in the afternoon. Indeed, the Mishna (Rosh Ha-shana 4:4) implies that Shir shel Yom was recited at Mincha too!
The Mishna Berura (122:16) explains that in the Beit Ha-mikdash they often omitted Shir shel Yom at Mincha, as the libations brought with the tamid shel bein ha-arbayim often lasted until after dark. Alternatively, the Arukh Ha-shulchan (123:2) explains simply that as reciting the song of the day is merely a “remembrance” of the practices in the Beit Hamikdash, one daily recitation suffices.
On days upon which Tefillat Mussaf is recited, some communities recite Shir shel Yom after Shacharit and before the Torah reading, while some recite it after Mussaf (see Magen Avraham 122:4).
Interestingly, the Ramban (Shemot 20:7) posits that whenever one refers to a weekday by its ordinal (e.g., referring to Tuesday as “the third day,” counting toward Shabbat), he fulfils the Biblical commandment to remember the Sabbath. Thus, we fulfil a mitzvah when we recite Shir shel Yom with the introduction “Today is the _______ day of the week.”