The journey of Joseph's brothers to Shechem marks a critical boiling point in their accumulated hatred and serves as the first step in a chain of events that will eventually bring the entire family down to Egypt. They intentionally travel far from their father's home to a region known for danger. Choosing Shechem is a calculated move to distance themselves from Joseph and his damaging reports. They assume Jacob will never dare send his favored son to such a perilous area, and if they decide to harm him there, they can easily pin the blame on the hostile local residents [מלבי״ם]. Another perspective suggests the trip is practical, aimed at establishing a strong claim over the lands Jacob previously bought or conquered in the region [ברכת אשר]. Even though the area remains dangerous following their earlier violent conflict over Dinah, the brothers feel secure, trusting in God and knowing that a divine terror has fallen upon the surrounding Canaanite cities [רד״ק].
Ancient scribal traditions place special marks over the text here, acting as a subtle erasure that separates the brothers' actions from the flock itself. This implies that they do not merely go to pasture the animals, but rather go to "pasture themselves." The primary approach among commentators explores the deeper implications of this self-serving journey. One view explains that the brothers give themselves over to eating, drinking, and physical pleasures to escape their father's strict authority [רד״ק, הדר זקנים]. They even slaughter and eat from their father's flock without permission, illustrating how one offense inevitably leads to another [העמק דבר, צאינה וראינה]. Initially, this heavy indulgence in food and drink is an attempt to numb the pain and intense jealousy caused by Joseph's dreams [לבוש האורה]. In reality, however, it only feeds their darkest impulses, stripping away their moral restraints and making them vulnerable to the terrible crime of plotting their brother's murder [תורה תמימה, גור אריה, משכיל לדוד].
Taking a different angle, some explain that this self-feeding is not about food at all, but rather about leadership and taking counsel. The brothers distance themselves specifically to hold a private council and plot their next move against Joseph [מזרחי]. On a completely different level, this concept of feeding themselves carries a profound hint about God's hidden providence. While the journey is born out of bitter jealousy and conflict, it is the very action that sets the stage for their ultimate survival. In a prophetic sense, they are going to "feed themselves" by unknowingly preparing their own future sustenance for the severe years of famine that will eventually strike [רא״ש, חתם סופר, דברי דוד, ריב״א].
Alongside these deep insights, a more straightforward reading maintains that the phrasing is simply standard biblical grammar [ריב״א, ברטנורא]. It might also indicate that they only take a portion of the flock, or simply that the brothers nourish themselves right alongside the animals in a suitable grazing area [חזקוני].