Weekday struggle versus Shabbos rest

אא"ז מו"ר ז"ל הגיד בענין הבארות עשק שטנה הוא עבודת ימי המעשה ורחובות הוא בשבת.

My grandfather, my teacher and master of blessed memory, said regarding the wells — Eisek and Sitnah represent the avodah of the weekdays, while Rechovos represents Shabbos.

Citing his grandfather (the Chiddushei HaRim), the Sefas Emes reads Yitzchak's three wells as a parable: the two contested wells, Eisek ("contention") and Sitnah ("enmity"), stand for the struggle of the workweek, while Rechovos ("wide spaces") stands for Shabbos.

כי בחול משיגין אלה הבארות ע"י המחלוקות ומריבות עם היצה"ר.

For during the weekdays one attains these wells through quarrels and disputes with the yetzer hara.

On weekdays a person reaches his spiritual "wells" — the wellsprings of holiness — only through constant battle and friction with his yetzer hara, which is why those wells are named for strife.

ובשבת בא ע"י מנוחה מעצמו.

But on Shabbos it comes through rest, of itself.

On Shabbos the same wellspring of holiness is reached not through struggle but through menuchah (rest); it flows on its own, as a gift.

ולכן נק' רחובות כי הרחיב ה' לנו.

Therefore it is called Rechovos, "for Hashem has widened for us."

The name Rechovos expresses expansiveness — on Shabbos Hashem widens the space and the flow of blessing is no longer cramped by struggle.

כי כשבא ע"י מעשה האדם א"י להתפשט הרבה שמביא לידי חסרונות.

For when it comes through a person's own effort, it cannot spread out very far, since that effort brings limitations and shortcomings.

Whatever a person achieves through his own striving is inherently limited and accompanied by deficiencies, so it cannot expand fully.

אבל בש"ק שבא ע"י השי"ת בלבד יש בו ברכה ומתרחבין הדברים וז"ש כי הרחיב ה' לנו ופרינו בארץ:

But on the holy Shabbos, since it comes from Hashem alone, there is blessing in it and matters expand — and this is the meaning of "for Hashem has widened for us and we shall be fruitful in the land."

Because the bounty of Shabbos comes purely from Hashem and not from man's limited effort, it carries true blessing and expands without limit, allowing one to "be fruitful in the land."

Summary: Yitzchak's three wells symbolize two modes of avodah — the weekday service of Eisek and Sitnah, attained through struggle with the yetzer hara and therefore limited, versus the Shabbos service of Rechovos, which comes from Hashem alone as effortless rest and therefore carries unlimited blessing and expansion.