The Akeidah as a request, accepted with joy

בענין העקידה קח נא כו' נראה כי מאחר שהבטיחו ביצחק יקרא לך זרע נאמר לו בלשון בקשה פי' שביקש הקב"ה ממנו שימחול לו המתנה ושיעלהו לעולה וזה שבח הגדול בנסיון הזה שלא נאמר לו בלשון ציווי רק אם חפץ בדבר זה.

Regarding the Akeidah, "Take, please, etc." — it appears that since Hashem had already promised him "through Yitzchak shall your seed be called," it was said to him in the language of a request. That is, the Holy One asked of him that he forgo the gift and bring him up as an olah (offering). And this is the great praise of this nisayon (test): that it was not said to him as a command, but only "if you so desire this matter."

The word "na" ("please") shows that Hashem did not command Avraham to bring Yitzchak as an offering — He requested it. Since Hashem had already guaranteed that Yitzchak would carry on Avraham's line, the Akeidah was framed as Avraham being asked to willingly give back the very gift he had been promised. The greatness of the test lay precisely in that it was left to Avraham's own free ratzon (will), not imposed as a decree.

ואברהם אע"ה באהבתו לקיים רצון המקום הלך בשמחה לשוחטו.

And Avraham Avinu, in his love to fulfill the ratzon Hashem (will of the Omnipresent), went with joy to slaughter him.

Avraham was not coerced. Out of his ahavah (love) for Hashem and his desire to do the divine will, he went with simchah (joy) to carry out what was only asked of him — turning a mere request into a whole-hearted act of devotion.

וכ' יחידך שבודאי הי' יכול להאמין כי יתן לו בן אחר כמו שנתן לו זה לעת זקנתו.

And it is written "your only one" — for surely he could have believed that Hashem would give him another son, just as He had given him this one in his old age.

The Torah stresses "your only one" to underscore the difficulty. Avraham could easily have reasoned that Hashem, who gave him Yitzchak miraculously in old age, could give him another son. The Torah closes off that consolation to show the full weight of what Avraham accepted.

אבל אמר לו כי אין לו עוד בן רק יצחק ושיעלהו לעולה באופן שנותן את כל זרע ישראל בעקידה זו וכל זה קיבל עליו בשמחה:

But He told him that he has no other son but Yitzchak, and that he should bring him up as an olah — in such a manner that he was giving over all the seed of Yisrael in this Akeidah; and all of this he accepted upon himself with joy.

Because Yitzchak alone carried the future of all Bnei Yisrael, in binding him Avraham was in effect placing the entire destiny of his nation upon the altar. Knowing this, Avraham still accepted it all with simchah — embedding that wholehearted self-surrender into the spiritual inheritance of every Jew.

Summary: The Akeidah was posed to Avraham not as a command but as a request, leaving room for his free will; and out of pure love for Hashem he joyfully gave back the son who embodied the entire future of Bnei Yisrael, planting that wholehearted devotion into his descendants forever.