Genesis 42:37

‘And Reuben spoke to his father, saying, “You may kill my two sons if I do not bring him to you. Hand him over to me and I will bring him back to you again.” '

Reuben is concerned to go straight back to obtain Simeon's release. He reveals here something very admirable in his character. Things may look foreboding but he is prepared himself to take the risk in order to obtain, if at all possible, his brother's release, and he is prepared to die in the attempt. But he realises how his father is feeling. So he uses the strongest argument he can. If he does not bring Benjamin back then his father can kill his two sons. He will then fully share in the sufferings of his bereaved father. But his father will have none of it.