On most days of the Jewish year (including Yom Kippur) the middle section of the Amida prayer remains unchanged in all services except for musaf. Shabbat is different. The opening paragraphs of the “Holiness of the Day” blessing on Shabbat are different in each service. On busy weekdays, the unchanging prayers are an anchor; the holiday are laden with enough meaning even if the Amida lacks variety but on Shabbat we have time, and the prayers themselves are an important element of our day. Not only are the prayers different but there is a logical progression from one to the next. I never noticed that progression until I read an essay by Rabbi Gordon Tucker on the subject. My treatment is a little different from his but without having read his essay, I might never have given the issue any thought.
On Friday night, we begin “You sanctified the seventh day in Your name, the culmination of the creation of heaven and earth." God here acts alone, only He worked to create the world and only He rests and sanctifies the Sabbath; this is a cosmic Sabbath that exists with or without us. Recalling the Sabbath of the universe, we acknowledge that the world and resources exist not only for our benefit. We may use them but also must protect them.
In the morning, God is joined by “Moses who rejoiced in his portion” and we are enjoyed to keep the Sabbath as an element of Israel’s covenant with God. The prayer notes that the Sabbath was given in the Ten Commandments but quotes a verse emphasizing the covenant: “The people of Israel shall keep the Sabbath, observing the Sabbath throughout their generations, as a covenant forever.” We have moved from creation to revelation, from primordial time to historical time.
In Musaf, we are aware of the shortcomings of the present and look forward to the future, but in Mincha, the future has already arrived. We say "You are One and Your name is One” a phrase recalling the end of Aleinu. The people of Israel are one, live in Israel and keep the Sabbath., Truly a vision of redemption!
On Friday evening, we began with the hope and anticipation of the cosmic Sabbath. On Saturday morning, the light of Torah gives us a framework for our work and rest, a connection to something larger than ourselves. In the bright noontime, we see the flaws of the present and look towards the future. And on Saturday afternoon, just before we are returned to the profane world, we have a glimpse of redemption, in hopes that it will motivate us to direct our efforts in worthy directions.
I quote Rabbi Tucker:
In the romantic dusks of Friday and Saturday evenings, we may dream idyllically of past and future. But in the bright light of Shabbat morning, we are to recognize that only through human actions, only through the gift [of Torah] can God’s promises be fulfilled… We had no hand in creation. But through revelation of Torah we may acquire a saving role in redemption. (in My People’s Prayer Book, Vol. 10: Shabbat Morning, p. 14)