What does Genesis 43:8 mean?
When Jacob's ten oldest sons went to buy grain during a famine (Genesis 42:1–2), they came back with a missing brother (Genesis 42:24) and a command from the Egyptian governor. To prove they were not liars, they had to return with their youngest brother, Benjamin (Genesis 42:19–20). Judah and his brothers know any trip to Egypt to buy grain will fail if they don't take Benjamin along. Jacob has resisted this, preferring to abandon Simeon rather than risk his favorite son. He continues to blame his older sons for putting him into this situation (Genesis 42:6).Jacob doesn't want to risk losing the only remaining son of his beloved late wife Rachel. However, the only alternative is to allow the family to starve to death. So, Judah asks outright that Jacob entrust Benjamin—"the boy"—to his personal safekeeping in order that all of them might survive this famine. In the following verse, Judah will offer his own life as a pledge of safety for Benjamin (Genesis 43:9).
This is an interesting turn of events, as Judah was among the brothers who wanted to kill Joseph, Jacob's former favorite son, out of jealousy, some twenty years prior (Genesis 37:18–20). Judah then hit on the idea of selling Joseph as a slave, instead (Genesis 37:26–28). What neither Judah nor the other brothers know is that the Egyptian governor is that very Joseph (Genesis 42:8).