In 42:37 Reuven offers Yaakov to "kill" his 2 sons "et shtei bonai Tamit" if he fails to restore Binyamin.
[Question: why TWO sons and not one or four?]
Yaakov refuses. Rashi in 42:38 explains that Yaakov saw Reuven's offer as from a "B'chor Shoteh" because how would Yaakov gain by killing his own grandchildren.
Well just WHAT was Reuven Thinking any way?
Let's presume that Rashi is correct regarding YAAKOV's perspective. What DIFFERENT perspective did Reuven have?
My friend R Joel Stern explains Reuven's POV
In P. Vayeishev Yehudah Sells Yosef and then later goes on to bury HIS first two sons
Now Reuven did not know WHY those two sons died, so he simply assumed it was retribution for "selling Yosef"
Reuven was saying he would be willing to RISK the lives of his two sons if he failed to protect Binyamin. [Now we know why specifically TWO]
But Yaakov could not have seen the causal connection to Yehudah because Yaakov was - after all - clueless about Yehudah's role. And Reuven was making an offer to risk his sons based upon his [mis]perception of the deaths of Yehudah's sons
And then Yaakov missed this point and concluded that Reuven's offer was "shtuyot" because it was pointless to harm him his own grandchildren.
Interestingly, as per this, Reuven, like Yaakov, misperceived related situations. Like Father Like Son?