Genesis 37:21

And Reuben heard it, and he delivered him out of their hands; and said, Let us not kill him.

The brothers conspired together to kill Joseph, but Reuben heard their plot and delivered him out of their hands, urging them not to kill him. He warned them that murdering Joseph would bring guilt upon them and bring God's curse upon them. He proposed instead that they leave Joseph alive in a pit without laying hands on him to harm him. His secret plan in this was to keep his brothers from harming Joseph so that he could later rescue him himself and return him to his father.

Instead of being killed, Joseph was thrown into a pit and then sold into slavery. The brothers' attempt to keep Joseph from rising to power was overruled by God and led to his dominion over them and his becoming a savior to his family, yet this outcome did not lessen their guilt. The episode belongs to Joseph's experience of wrongful persecution: though virtuous, he was maligned and treated as a criminal, yet God gave him victories even while he appeared to suffer for doing right.