After accusing his brothers of espionage and demanding they bring their youngest sibling, the escalating tension culminates in physical confinement. Joseph takes a severe step to break their resistance, yet he carefully maintains clear boundaries to prevent actual harm. The primary approach among commentators is that the brothers are placed in a genuine detention facility or locked together in a single room within Joseph's house [רלב״ג], rather than simply being watched by guards in an open area.
The motivation behind this imprisonment stems from both psychological strategy and practical necessity. On a moral level, Joseph intends to frighten his brothers and cause emotional distress, while strictly avoiding any physical injury or financial loss [רד״ק]. His goal is to bring them to a state where they will deeply appreciate their eventual release. By freeing them so their families will not starve, he proves that he truly fears God [רמב״ן, הטור הארוך]. At the same time, the imprisonment is a direct response to the brothers' stubborn refusal to comply with his initial demands. When Joseph first insists that only one brother return to retrieve the youngest, they flatly refuse. They know their father will never entrust the boy to an Egyptian messenger, and they realize that returning without the entire group will cause their father fatal grief. Preferring to sit in a cell together rather than witness their father's sorrow, no brother is willing to undertake the mission. Viewing this refusal as outright rebellion, Joseph locks them all away until they agree to choose a representative or until his anger subsides [שד״ל, מלבי״ם, ביאור יש״ר, רמב״ן, הטור הארוך].
The specific duration of three days offers several layers of meaning. Practically, Joseph may not have predetermined this timeframe. He simply confines them until they surrender, ultimately changing his mind after three days [שד״ל, ביאור יש״ר]. However, others suggest that three days is the exact period required to fully establish and solidify a state of trial [צפנת פענח].
On a deeper level, the number three carries significant historical and moral weight. The days in prison correspond directly to the three actions the brothers committed against Joseph: stripping him of his tunic, throwing him into a pit, and selling him into slavery [קיצור בעל הטורים]. Furthermore, these three days act as a moral counterbalance to the actions of Shimon and Levi in Shechem. While the brothers exploited the third day of the townspeople's pain to kill them despite their acceptance of circumcision, Joseph chooses the third day to release his brothers, declaring his fear of God and his preservation of the covenant [שפתי כהן]. Finally, this imprisonment serves as a subtle foreshadowing of the future Greek exile, which is seen as a consequence of selling Joseph. During that exile, three harsh decrees were imposed upon the Israelites: prohibitions against keeping the Sabbath, sanctifying the new month, and performing circumcision [אדרת אליהו].