In Parashat Miketz, we read that Yaakov sends his remaining sons to Egypt to purchase grain from the Egyptian vizier, who, unbeknownst to them, is none other than their missing brother, Yosef. Yosef accuses them of coming to Egypt to spy the country, and demands that they bring their youngest brother, Binyamin, as proof of their innocence. He keeps Shimon as prisoner in Egypt to guarantee the other brothers' return. But Yaakov refuses (initially) to allow Binyamin to join his brothers; having lost his first son from Rachel, Yaakov refuses to put Rachel's only other son, Binyamin, in a situation of danger.
As Yaakov's sons try convincing him to allow Binyamin to go, Reuven, the oldest, employs a strikingly peculiar means of persuasion: "You may kill my two sons if I do not bring him back to you. Put him in my care, and I will return him to you" (42:37). Chazal, cited by Rashi (to 42:38), note the absurdity of this promise. Rashi writes, "He [Yaakov] did not accept Reuven's comments. He said: This is a foolish firstborn! He says he will kill his sons – are they only his sons, and not my sons?!" Reuven's pledge to kill his own sons, Yaakov's grandchildren, if he fails to bring Binyamin back safely, appears to defy reason. What possible explanation could there be for Reuven's offer?
Rav Menachem Kasher (in Torah Sheleima) cites two approaches to understanding Reuven's promise. The "Minchat Yehuda" suggests that Reuven did not actually "offer" to kill his sons, but rather made this remark as an oath of sorts. It is as if he had said, "I am so confident that I can bring Binyamin back that I would be willing to bet my sons' lives on it." Others, such as the Taz (in his "Divrei David Turei Zahav") and the Chatam Sofer (in Torat Moshe and in responsa, O.C. end of 208), claim that Reuven promises to forfeit his sons' right to a share in Eretz Canaan, which he allegorically describes as "death."
We may, however, suggest a different explanation. In the previous verse, Yaakov responds to the brothers' report of their experiences in Egypt. He wails, "You have bereaved me! Yosef is no more and Shimon is no more, and now you would take away Binyamin; these things always happen to me!" Why does Yaakov point an accusing finger at his sons, claiming that they "bereaved" him? Rashi writes: "This shows that he suspected that they killed him or sold him like [they did to] Yosef." Indeed, according to Rashi, Yaakov has begun entertaining thoughts of suspicion against his sons. Twice his sons have come to him and claimed that one of their brothers has disappeared or been captured. He cannot but wonder whether these nine brothers have taken some part in the loss of the other two.
It is in response to this suspicion, perhaps, that Reuven declares, "You may kill my two sons if I do not bring him back." He tells his father that he can be trusted with Binyamin, and if he does not bring him back safely, then this will confirm Yaakov's suspicions that the brothers – himself in particular - eliminated Yosef and Shimon. Reuven then decrees his own sentence if this should indeed occur: he should lose his two sons, as punishment for, according to Yaakov's theory, having killed or sold his two brothers.
If this is correct, then Reuven here also sends an encoded message to his brothers. He in effect says, "Father, you can trust me with Binyamin; I do not kill or sell my brothers." Yesterday, we suggested (based on Midrashim) that Reuven and his brothers had been entangled in a fundamental dispute as to how to respond to Yosef's dreams of leadership over the family. Whereas Reuven argued for the brothers' acceptance of Yosef, they, of course, vehemently decided upon his elimination. Reuven here subtly – or not so subtly – emphasizes to his brothers that he, unlike them, can be trusted with Binyamin, and Yaakov has no reason to suspect him as he suspects the others.