בראשית, פרק מ״ג, פסוק ה׳

The brothers present Jacob with a logical argument based on a complete lack of alternatives and absolute necessity [רש ר הירש]. They lay out a clear dilemma weighing certainty against doubt. If Benjamin remains at home and they do not travel to Egypt, the entire family faces the absolute certainty of starving to death. Conversely, if Benjamin makes the journey, there is only a possibility that disaster might strike him. Faced with this choice, logic dictates that they must set aside the uncertain risk in order to choose the path that saves them from guaranteed death [בכור שור].

Furthermore, the warning issued by the Egyptian ruler was not merely a formal threat, but the establishment of an absolute fact. He made it unequivocally clear that they would have no opportunity to appear before him without their brother. Since securing grain requires a meeting with the ruler, making the journey without Benjamin would be entirely useless. It would result in no food and would only expose the brothers to unnecessary danger [העמק דבר].