Eliezer's prayer sweetens Yitzchak's din

במדרש עבד משכיל ימשול בבן מביש כו' ובתוך אחים כו' אלקי אדוני אברהם כו'.

In the Midrash: "A wise servant will rule over a shameful son... and among brothers..." (Mishlei 17:2) — "the God of my master Avraham..." (Bereishis 24:12), etc.

The Midrash applies the verse about a "wise servant" to Eliezer, Avraham's servant, who prayed at the well using the words "God of my master Avraham."

דיש להבין מה הי' צורך לתפלה זו כי לא הי' לו רק לעשות שליחותו.

For one must understand: what need was there for this tefillah? He had only to carry out his mission (shlichus).

The Sefas Emes asks why Eliezer prayed at all, since his task was simply to fulfill Avraham's errand of finding a wife for Yitzchak.

גם למה נכתב בתורה התפלה.

Also, why was the tefillah written in the Torah?

And why does the Torah record his prayer in such detail, if it were merely a servant's request?

לכן נאמר שהי' הכל לטובת בנ"י.

Therefore we say that it was all for the good of Bnei Yisrael.

The answer is that Eliezer's prayer carried a deeper purpose, serving the future benefit of all Bnei Yisrael.

לאשר אבינו יצחק לקח לו מדה"ד כמ"ש פחד יצחק ולא הי' אפשר להתקיים במדה זו.

Because our father Yitzchak took for himself the attribute of strict judgment (middas ha'din), as it is said "the Dread of Yitzchak" (Bereishis 31:42) — and it would not be possible to endure with this attribute alone.

Yitzchak embodied the trait of din (strict judgment/gevurah); a world or a family line governed solely by unmitigated din could not survive.

לכן סיבב השי"ת להיות לו רבקה לאשה שהיתה בעלת חסד ביותר ובזה נמתק קצת הגבורות של יצחק.

Therefore Hashem brought it about that Rivkah should be his wife, for she was exceedingly a baalas chesed (a woman of kindness), and through this the gevuros (severities) of Yitzchak were somewhat sweetened.

Hashem arranged Rivkah's exceptional chesed to balance and "sweeten" Yitzchak's din — uniting kindness with strict judgment so the line could endure.

ואליעזר הבין זה כי יצחק דורך לו דרך אחר.

And Eliezer understood this — that Yitzchak walks a different path.

Eliezer perceived that Yitzchak's avodah ran along the path of din, distinct from Avraham's way.

והוא הי' דבוק במדת החסד שהי' תלמידו של אברהם.

And he (Eliezer) was attached to the attribute of chesed, for he was a disciple of Avraham.

As Avraham's talmid, Eliezer himself was bound to the middah of chesed, Avraham's defining trait.

ולכן התפלל שיזמין לו בעלת חסד.

Therefore he prayed that Hashem should arrange for him (Yitzchak) a baalas chesed.

Recognizing the need to temper Yitzchak's din, Eliezer specifically prayed that the chosen wife be a woman of chesed.

וז"ש ובה אדע כי עשית חסד כו'.

And this is what he said: "And by her I shall know that You have done kindness (chesed)," etc. (Bereishis 24:14).

Eliezer's sign was rooted in chesed — the maiden who would draw water for him and his camels — because he was seeking precisely the trait of kindness to balance Yitzchak.

וז"ש ימשול בבן מביש שבמעשיו המתיק מדת יצחק בעל כרחו.

And this is the meaning of "he will rule over a shameful son" — that through his actions he sweetened the attribute of Yitzchak, as it were, even against its nature.

Eliezer, the "wise servant," "ruled over the son" in the sense that his deeds brought about the sweetening of Yitzchak's din through Rivkah's chesed.

ובתוך אחים יחלק כו' כי הי' במעשיו טובה לכלל ישראל כנ"ל:

"Among brothers he will share an inheritance," etc. — for through his deeds there was a benefit to the entire klal Yisrael, as above.

Because Eliezer's prayer secured the chesed that would temper Yitzchak's line, his deeds brought lasting good to all of Bnei Yisrael, earning him a "share among the brothers."

Summary: Eliezer's prayer at the well was not a mere servant's request but an act for the eternal good of Bnei Yisrael. As Avraham's disciple, bound to chesed, he understood that Yitzchak embodied the unsustainable attribute of din, and so he prayed specifically for a baalas chesed — Rivkah — whose kindness would sweeten Yitzchak's severities. Thus the "wise servant" of the verse ruled over and tempered Yitzchak's middah and brought benefit to all of klal Yisrael.