The death of a family patriarch often destabilizes the unity of a family. Following Jacob's passing, the brothers, still carrying the weight of their past guilt, become highly sensitive to shifts in their environment. They begin to suspect that the peace they enjoyed with Joseph was entirely dependent on their father's presence [רש״ר הירש].
The primary approach among commentators points to a sudden change in Joseph's hospitality as the trigger for this anxiety. During Jacob's lifetime, Joseph regularly hosted his brothers at his table. Once Jacob died, this stopped. However, this distance was not born of malice, but of humility. While Jacob was alive, he naturally sat at the head of the table. Without him, Joseph faced a dilemma. He did not want to disrespect Reuben, the firstborn, or Judah, the leader, by sitting above them, yet his royal position prevented him from sitting below them. His solution was to eat separately [רש״י, שפתי חכמים, משכיל לדוד, צרור המור, דברי דוד]. Others suggest this distance was a political calculation to prevent the Egyptians from feeling threatened by the brothers' combined power [גור אריה], or conversely, a deliberate move by Joseph to prove that even without their father's oversight, he would not use his unchecked power to harm them [יריעות שלמה].
Alternatively, the brothers' anxiety may have been triggered on their journey back from burying their father. Along the way, Joseph paused at the very pit into which they had once thrown him, offering a blessing to God for his miraculous survival. Witnessing this, the brothers panicked, assuming the trauma was still fresh in his mind and that he was dwelling on the injury [קיצור בעל הטורים, ריב״א, צרור המור, חזקוני, הדר זקנים]. Another perspective suggests that during the days of mourning, as the family sat together and conversed, the brothers finally comprehended the true depth of the anguish Joseph had endured, which only magnified their dread [קונטרס חיבה יתירה].
Overcome by this dread, they worry about Joseph harboring a deep, hidden grudge or actively plotting against them [אבן עזרא, העמק דבר, מחוקקי יהודה, צרור המור, הדר זקנים]. Their reaction to this potential animosity is complex. The most straightforward understanding is a simple expression of fear that Joseph might now hate them and retaliate [רש״י, אבן עזרא, שד״ל, ביאור יש״ר, ביאור שטיינזלץ]. Others view their reaction as a wish for damage control, hoping that if Joseph does despise them, he will merely keep the hatred hidden in his heart rather than acting upon it, or at least wishing the consequences would go no further than silent resentment [קיצור בעל הטורים, הטור הארוך, בכור שור, הכתב והקבלה].
A deeper psychological and spiritual reading suggests the brothers actually wished for Joseph to retaliate immediately. Psychologically, confronting open hostility is often easier than navigating suppressed anger masked by superficial kindness, because expressed anger eventually burns out [פרדס יוסף]. Furthermore, receiving favors from an enemy can invite spiritual judgment, making direct punishment preferable [חתם סופר]. On a profound spiritual level, the brothers possessed a prophetic awareness of the future suffering their descendants would endure as a consequence of selling Joseph. They prayed that Joseph would enact his revenge upon them in the present world, settling the spiritual debt measure for measure, so that the burden would not fall upon future generations [אור החיים, תיבת גמא, שפתי כהן, אלשיך, צרור המור].
Ultimately, their fear was not that Joseph would simply execute them, as taking a life would be an effortless act for an absolute ruler. Instead, they dreaded a calculated, precise retribution. They worried that Joseph would orchestrate a sophisticated scheme to sell them into slavery, mirroring the exact fate they had once forced upon him [העמק דבר, ביאור יש״ר].