A desperate cry at the edge of an empty pit marks the collapse of Reuben’s secret plan to rescue his younger brother. Returning to find Joseph missing, the eldest brother is consumed by a sudden rush of heartbreak, anxiety, and heavy responsibility. He was not present when the others sold the boy. His absence occurred either because he was away fasting in sackcloth, repenting for a previous moral failure [רד״ק, צאינה וראינה], or because it was simply his turn in the brothers' rotation to serve their father Jacob [צאינה וראינה, שפתי כהן]. Finding the pit empty, he immediately assumes his brother was either stolen or murdered by the others [רד״ק, ביאור יש״ר].
In his anguish, Reuben refers to his seventeen-year-old brother as a young child. This framing highlights Joseph's innocence, emphasizing that he is a youth who has not yet reached an age of strict accountability and certainly does not deserve such a cruel fate [העמק דבר]. His reaction is deeply personal, heavily emphasizing his own distress and isolation as he faces the reality of the disaster [אבן עזרא, מחוקקי יהודה].
His desperate question of where he can possibly go now carries many layers of meaning. The primary approach among commentators is that this is a pure expression of despair: where can he possibly run to escape his father's immense sorrow? [רש״י, מזרחי, שפתי חכמים, ביאור יש״ר]. Others suggest he is not talking about running away, but rather realizing he is entering a new, harsh reality filled with trouble and grief [שד״ל]. It is the reaction of a man entirely overwhelmed by tragedy, his mind wandering frantically in search of a moment of peace [הכתב והקבלה]. Some view his panic more practically, wondering where he should even begin to search [בכור שור], or bitterly regretting that he ever came to the pit in the first place [רשב״ם]. On a deeper level, his reaction reflects a fear of exile, wondering where he will be banished as an unintentional murderer, much like Cain [העמק דבר], or even a profound terror of losing his portion in the World to Come [שפתי כהן, קונטרס חיבה יתירה].
Beyond the grief for his brother, a crushing sense of guilt weighs on him. Reuben feels responsible because it was his own advice to throw the boy into the pit to begin with [העמק דבר]. He is ashamed that he did not act with enough courage to save him outright, perhaps because his previous sin had weakened his self-confidence [רש״ר הירש]. As the eldest, he knows the ultimate responsibility will fall squarely on his shoulders [שטיינזלץ, צאינה וראינה].
Worst of all, he is terrified that Jacob will suspect him personally of harming Joseph. This suspicion would be entirely natural for two reasons. First, his own rights as the firstborn were taken away and given to this very brother, creating an obvious motive of jealousy [פענח רזא, רש״ר הירש, חזקוני, צאינה וראינה]. Second, because Joseph had previously brought bad reports to their father about the sons of Leah, Reuben fears being accused of taking revenge [חזקוני]. Ultimately, he feels completely trapped, believing there is nowhere left in the world where he can show his face without overwhelming shame [רש״ר הירש].