When they return and recount what had happened, Jacob replies “You have robbed me of Joseph, Simon is not with us and now you want to take Benjamin.” Reuben the eldest son then says to Jacob that he will be responsible for Benjamin and that of he fails Jacob can kill Reuben’s two sons.
This extreme and illogical suggestion only underlines the limitations of Reuben and explain why he is not regarded as the natural heir. Jacob will not relent. The famine gets worse and the corn runs out. Jacob wants the sons to go back to Egypt. But again, they tell him they cannot return without Benjamin. This time Judah steps up and says that they have to go. If they do not, everyone might die. Jacob relents and interestingly tells them to take gifts from the produce of the land, honey spices, nuts all things that are not affected by famine in the way grain is.
Why did Jacob refuse Reuben’s offer but relent when Judah came forward? One reason is the illogicality of Reuben’s offer. As if killing two children will do any good. It actually sounds very pagan. As if Reuben has been influenced by pagan custom. But Jacob already knew that the other brothers had ignored Reuben once before over selling Joseph. He had more confidence in Judah. His offer sounded more stable, more responsible. This is obviously a hint as to why Reuben will be overlooked as the leader after Jacob and Judah will become the pre-eminent tribe. But that, of course, is hundreds of years ahead.