What does Genesis 42:34 mean?
Nine of the ten sons Jacob sent to buy grain in Egypt (Genesis 42:1–5) have returned (Genesis 42:29–33). Jacob's sons are telling him what happened when they attempted to buy grain in Egypt. The lord of the land accused them of being spies. In attempting to convince him they were honest men, they told him about their youngest brother and father back in Canaan (Genesis 42:13). They don't realize this governor is their own brother, Joseph, sold into slavery twenty years earlier (Genesis 37:28; 42:7–8).This is the hardest part of the story for these men to explain to Jacob. The Egyptian ruler—secretly their brother, Joseph—kept Simeon, demanding they return with their youngest brother Benjamin to prove their story. If they come back with Benjamin, they will get Simeon back and be allowed to trade freely in Egypt.
Jacob's sons knew he would not take this news well. Their lie about Joseph (Genesis 37:31–33) nearly killed Jacob with grief (Genesis 37:34–35). That may be why they left out key details about their three-day imprisonment (Genesis 42:17–18) and the Egyptian ruler's threat to kill them (Genesis 42:20) if they didn't prove themselves honest in this way.