Bittul of middos before truth

בענין העקידה כתיב על אחד ההרים וכו'.

Regarding the Akeidah it is written: "upon one of the mountains," etc.

The Sefas Emes opens with the pasuk commanding Avraham to bring Yitzchak as an olah on a mountain that Hashem would designate, and he will now read "one of the mountains" as hinting at a specific avos figure.

הרים נקראו האבות.

The Avos are called "mountains."

Chazal compare the Avos — Avraham, Yitzchak and Yaakov — to mountains, the lofty foundations of Klal Yisrael.

אחד ההרים יעקב המיוחד שבאבות.

"One of the mountains" refers to Yaakov, the most singular of the Avos.

The word echad ("one," but also "the unique one") points to Yaakov, who unites and completes the avodah of all the Avos.

ושניהם אברהם ויצחק הוצרכו למסור כחם ליעקב מדות פרטיות שבהם חסד לאברהם ופחד יצחק.

Both of them, Avraham and Yitzchak, had to hand over their strength to Yaakov — their particular middos: chesed (kindness) to Avraham and pachad (awe/fear) to Yitzchak.

Avraham embodies the middah of chesed and Yitzchak the middah of gevurah/yirah, but each of these is a single, partial trait that needed to be channeled into Yaakov.

ויעקב מדת אמת הוא מראש ועד סוף והכל משלימים אליו.

Yaakov is the middah of emes (truth), from beginning to end, and everything is completed in him.

Emes is not one trait alongside others but the all-encompassing measure that holds true at every point; thus the partial middos of the other Avos find their wholeness in Yaakov.

לכן אברהם כבש רחמיו והחסד שבו לעקוד את בנו.

Therefore Avraham suppressed his mercy and the chesed within him in order to bind his son.

At the Akeidah Avraham had to override his own defining middah of chesed — his natural compassion — for the sake of a higher truth.

ויצחק מסר כל עצמו לשרוף והכל בעבור אחד ההרים.

And Yitzchak gave over his entire self to be burned — and all of this was for the sake of "one of the mountains."

Yitzchak too set aside his own middah, surrendering his very life; both Avos subordinated their personal traits for the sake of the unifying truth that is Yaakov.

וללמוד מזה שיבטל האדם כל המדות בעבור האמת:

And to learn from this that a person should set aside (be mevatel) all his middos for the sake of emes.

The lesson of the Akeidah is bittul: a person must be ready to nullify even his finest natural traits when they stand in the way of the truth of ratzon Hashem.

Summary: The Akeidah teaches that even the holiest middos — Avraham's chesed and Yitzchak's pachad — are only partial; both Avos surrendered their defining traits for the sake of Yaakov, the middah of emes, teaching every Jew to be mevatel his own middos before the truth of Hashem.