Reading this section of Genesis, the contrast between Reuben and Judah always stands out incredibly starkly to me.
In chapter 37, Reuben, as the oldest son, should be taking charge and leading his brothers. He should be the future patriarch of the family, but here, he won't even take a stand against his brothers about something obviously wrong. As the rest of the group is planning to kill Joseph, the most Reuben is willing to stand up to them is to say they should throw him in a pit to starve to death instead of killing him themselves. Yes, his intention is to sneak back later and rescue Joseph, but he isn't willing to take personal responsibility here and do what should be done for his brother.
Judah, in contrast to Reuben, seems to be somewhat of a ring leader in all this. Chapter 37 never tells us whose initial idea it was to kill Joseph, but Judah is the one we see speak up about selling him off. While his brother is in the pit, begging for his life, Judah is thinking about how they can profit off the situation and is entirely unashamed to speak up and suggest they sell him as a slave.
This is our primary introduction to the character of these two men; the one that should be leading is timid, and more about protecting himself than those he should be responsible for, and Judah, while unafraid to step up and lead, does it from a place of callous selfishness.
As the story goes on and we get to chapter 42, we see just how little Reuben has matured over the years. When the brothers first return from buying food in Canaan and tell Jacob what happened, Jacob tells them that Benjamin is not going back with them. Reuben, ever the strong leader, guarantees Benjamin’s safety by telling Jacob he can kill Reuben’s two sons if he doesn’t bring Benjamin back safely. His version of taking responsibility costs him absolutely nothing and is “leadership” at the potential cost/harm of his children. In short, Reuben didn’t learn a thing from his failure to stand up to his brothers when they were going to kill Joseph, and this episode just shows how selfish and inept he really is.
But what about Judah? Judah is a completely different story. When Joseph’s brothers stand before him and he is saying Benjamin is going to stay as his slave, Judah asks to speak to him privately and asks to take Benjamin’s place as Joseph’s slave. While I don’t know this for sure, I imagine that Judah was impacted by the effect Joseph’s “death” had on his father. Judah resented Joseph for his father’s affection, and likely resented Jacob as well for showing such blatant favoritism to Joseph, making him easily able to sell his brother out. But when he saw and lived with the impact of his choice, whatever else did or didn’t happen in his heart over the years, he wasn’t willing to repeat the experience. When the rubber met the road, Judah was willing to give up his entire life in order to see his younger brother returned safely to his father.
Reuben lost his inheritance as the firstborn because he slept with one of his father’s wives, and Levi and Simeon both missed out on the chance to pick up what Reuben lost because of what they did in slaughtering an entire city. And Judah? Judah may very well have missed out on the opportunity as well because of his role in Joseph’s being sold into slavery, but his actions in Genesis 44 on Benjamin’s behalf betray a transformed heart and show Judah a man worthy of leading his family.