Adding the mundane into Shabbos holiness

וכתיב ויוסף אברהם ויקח אשה כו'.

And it is written, "And Avraham took another wife..." (Bereishis 25:1).

The Sefas Emes reads "va-yosef" (he added) as hinting at the theme of "adding" — tosefes — which he will connect to Shabbos.

י"ל שהוא בחי' תוספות מחול אל הקודש.

One could say that this is the aspect of the addition (tosefes) from the mundane into the holy.

"Va-yosef" alludes to tosefes Shabbos — the practice of adding from the weekday into the sanctity of Shabbos.

כי השבת הוא מיוחד לבני ישראל.

For Shabbos is uniquely the portion of Bnei Yisrael.

Shabbos is the special inheritance of Yisrael alone, set apart from the nations.

וזה שורש האבות.

And this is the root of the Avos.

The holiness of Shabbos is bound up with the spiritual root of the Avos.

והם ג' סעודות.

And they are the three meals.

The three Avos correspond to the three seudos of Shabbos.

ג' ברכות בכל מכל כל.

The three blessings: "in all" (ba-kol), "from all" (mi-kol), "all" (kol).

The Avos were each blessed with completeness — Avraham "with all," Yitzchak "from all," Yaakov "all" — which Chazal connect to the wholeness of Shabbos.

ואין ארור מתדבק בברוך.

And the cursed does not cling to the blessed.

The realm of blessing (the Avos, Shabbos) admits no admixture of curse or impurity.

לכן יש הבדלה בין קודש לחול.

Therefore there is a separation (havdalah) between the holy and the mundane.

Because blessing and curse cannot mix, a clear boundary divides the sanctity of Shabbos from the weekday.

ובשבת סט"א ערקת ומתגלה הברכה.

And on Shabbos the sitra achra (the side of impurity) flees, and the blessing is revealed.

When the impure force withdraws on Shabbos, the hidden blessing shines forth openly.

ובימי המעשה דסט"א שריא בעולם.

And on the weekdays, when the sitra achra is present in the world,

During the six workdays the side of impurity has a presence in the world.

אין הברכה מתגלה.

the blessing is not revealed.

So long as that impurity is active, the blessing stays concealed.

וע"י אמונה שמבטלין כל ימי המעשה להיות הכנה לשבת יכולין להעלות ימי המעשה מכלל ארור לברוך.

And through emunah, by which one nullifies all the weekdays to be a preparation for Shabbos, one is able to elevate the weekdays from the category of "cursed" to "blessed."

With emunah, a Jew treats the whole work-week as nothing but a preparation for Shabbos, and thereby lifts even the mundane days into the realm of blessing.

כדאיתא גבי אליעזר.

As it is taught regarding Eliezer.

Eliezer, servant of Avraham, is the example: though seemingly from the side of "cursed" (a descendant of Canaan), he was elevated into "blessed."

ולכן נק' סעודתא דמהימנותא.

Therefore it is called "the meal of faith" (seudasa di-mehemnusa).

The Shabbos meals are called the "feast of emunah," because it is faith that elevates the weekday into the blessing of Shabbos.

וכל זה לבני ישראל שהם מאמינים בני מאמינים.

And all of this applies to Bnei Yisrael, who are believers, the children of believers.

Only Yisrael, heirs to the emunah of the Avos, have the power to perform this elevation.

אבל יש תוספות מחול אל הקודש בכניסתו ויציאתו.

But there is an addition (tosefes) from the mundane into the holy, both at its entrance and at its departure.

We add to Shabbos from the weekday both before it begins and after it ends — extending sanctity into the mundane on both sides.

ולכן הוליד ישמעאל קודם יצחק ואח"כ בני קטורה:

Therefore he fathered Yishmael before Yitzchak, and afterward the children of Keturah.

The "addition" before and after the holy core is mirrored in Avraham's offspring: Yishmael preceding Yitzchak (the addition at the "entrance") and Keturah's children following (the addition at the "departure") — the mundane that brackets and is elevated toward the holy center.

Summary: "And Avraham added a wife" alludes to tosefes Shabbos, the addition from the mundane into the holy. Shabbos is the unique portion of Yisrael, rooted in the three Avos and the three meals, a realm of pure blessing from which the sitra achra flees. Through emunah a Jew turns the whole work-week into a preparation for Shabbos, elevating even the "cursed" weekdays into blessing — which is why the Shabbos meals are the "feast of faith." This addition before and after the holy core is hinted in Avraham fathering Yishmael before Yitzchak and Keturah's children after.