Sforno on Genesis 37:18/ספורנו על בראשית ל״ז:י״ח

1ויתנכלו אותו להמיתו, the root נכל always means to plan to do something evil. One example of the use of this word in this sense is found in Numbers 25,18 אשר נכלו אתכם, “who plotted against you.” The brothers had entertained the thought of causing Joseph’s death while they saw him from a distance. They did not think that he had come to make peace with them but that he was spying on them to either cause them to commit a sin which would bring their father’s curses on them or which would cause G’d to punish them. As a result of this, Joseph imagined he alone would survive as blessed of all of Yaakov’s sons. The expression ויתנכל in the reflexive conjugation described what a person fantasizes about in his mind, what imaginary scenarios he entertains in his head. You find the expression in Samuel I 28,9 אתה מתנקש בנפשי, “(the witch of Endor speaking to King Sha-ul who had disguised himself) “you are trying to trap me into forfeiting my life, trying to get me killed! The word להמיתו in our verse refers to Joseph causing the death of his brothers. [While it is true that the word is separated from the word אותו preceding it by the tone sign tipcha which refers to what came before, in the opinion of this Editor it should then have read להמיתם to cause their death,” instead of “to cause his death.” Ed.] We find the expression used in a similar sense in Deuteronomy 4,14 לעשותכם אותם, “so that you will fulfill them.” [the author describes the function of the transitive conjugation of the root נכל and עשה respectively, not any similarity of the subject matter under discussion in the two verses mentioned. Ed.] If we understand the thoughts described in our verse in this vein, we can solve the riddle of how the stones on the breastplate of the High Priest could have been inscribed with the names of all these brothers, if instead of being as righteous as such models ought to have been in order to serve as inspiration for us, they had indeed harboured such murderous thoughts without justification. Even if the brothers’ intention to sell Joseph had been based on mere hatred, how could such brothers qualify as inspiration for the Jewish people of the breastplate of the High Priest? We must therefore endeavour to understand the collective feelings of the brothers as being that they actually felt themselves threatened by Joseph’s aspirations and they were convinced that when one feels threatened one is entitled or even obliged to take measures to neutralise the source of the danger. This is even a halachic principle clearly spelled out in Sanhedrin 72. If we needed any proof for the truth of the brothers’ feelings, it is best provided by their conversation among themselves while in jail (42,21) when they felt that G’d had repaid them for their misdeeds. They did not regret selling Joseph, nor even having planned to kill him; the only thing they regretted and considered themselves guilty of was that they had not responded to Joseph’s pleas for mercy. In other words, even over 20 years after the event they were still convinced that Joseph had posed the sort of threat to their existence which entitled them to take extreme defensive action against him.