Shabbos as the source of the week

בפסוק מועדי ה' אשר תקראו כו' ששת ימים (תעבידו) [*תעשה] כו'.

On the passuk: "The appointed times of Hashem, which you shall proclaim… six days [shall work be done]…"

The Sefas Emes opens on the verse that lists the moadim (festivals), noting that the Torah immediately mentions the six weekdays and Shabbos before turning to the festivals — a juxtaposition that demands explanation.

ובמועדות כתיב אשר תקראו אותם במועדם.

And regarding the festivals it is written: "which you shall proclaim them in their appointed time."

For the Yamim Tovim the Torah stresses that each must be called out "in its appointed time" — each festival has its own fixed date on which its kedushah descends.

כי ביו"ט יורד קדושה מיוחדת בזמן ההוא.

Because on a Yom Tov a special kedushah (holiness) descends at that particular time.

Each festival draws down a unique holiness that belongs to its own day alone; that is why it must be "called in its appointed time."

אבל קדושת השבת צריכין לקרוא תמיד שהשבת מאיר לכל ימי המעשה לכן לא כ' בי' במועדו.

But the kedushah of Shabbos must be proclaimed always, for Shabbos shines into all the days of work; therefore "in its appointed time" is not written regarding it.

Shabbos is different. Its light is not confined to one day but radiates into the entire week, so the Torah does not limit it to "its appointed time" — its holiness must be drawn upon constantly.

והתחיל ששת ימים לומר שיכולין למשוך קדושה מהשבת לימי המעשה.

And the Torah began with "six days" to teach that one can draw kedushah from Shabbos into the weekdays of labor.

By placing "six days" right before the festivals, the passuk hints that the holiness of Shabbos can be extended into the ordinary workdays themselves.

וכן שמעתי ממו"ז ז"ל שלכן בשבת אין מברכין שהחיינו כמו ברגל.

And so I heard from my grandfather, of blessed memory, that this is why on Shabbos we do not recite Shehecheyanu as we do on a Yom Tov.

The Sefas Emes cites his grandfather (the Chiddushei HaRim): unlike the festivals, Shabbos is not marked with the brachah of Shehecheyanu.

משום דמיני' מתברכין כל שיתא יומין.

Because from it all six days are blessed.

Quoting the Zohar, Shabbos is the source from which the six weekdays receive their blessing.

נמצא קיום כל הימים ע"י השבת ולא שייך לברך שהחיינו עכ"ד ז"ל.

It emerges that the very existence of all the days is through Shabbos, and so it is not fitting to recite Shehecheyanu — these are his words, of blessed memory.

Since Shabbos is not a renewed beginning that arrives anew each year but the constant wellspring sustaining every single day, the brachah of Shehecheyanu, which marks a fresh arrival in time, does not apply to it.

[באמת צ"ע דבלא"ה לא שייך זמן רק הבא מרוחק שלשים יום]:

[In truth this requires further study, for in any case Shehecheyanu applies only to something that returns after an interval of thirty days.]

In a bracketed aside the Sefas Emes notes a halachic difficulty: Shehecheyanu is anyway only said over things separated by thirty days, whereas Shabbos returns weekly — so the reason may need refining.

Summary: Unlike the festivals, whose kedushah descends on a single fixed date, the holiness of Shabbos radiates continuously into all six weekdays and sustains them; therefore "six days" is placed beside the moadim to teach that we draw Shabbos-light into the week, and therefore — as the Chiddushei HaRim taught — no Shehecheyanu is recited on Shabbos.