What is so bad about being an "Am K'shei Oref"? Why does it negate the merit of inheriting Eretz Yisrael?
Seforno: Because a person who is stiff-necked sees only what he wants to see, and is incapable of turning his head to see what others show him, even when wise men show him that he is heading towards his own destruction. Consequently, his decisions cannot possibly be just and correct. 1
Oznayim la'Torah (in Pasuk 13): Moshe was accusing them of being stubborn - incapable of breaking old habits. Since they worshipped idols in Egypt, they were incapable of changing. 2
Seforno (in Pasuk 8): Moreover, his stubbornness prevents him from doing Teshuvah and the only solution is destruction - like we find after the sin of the Golden calf. See Sh'mos 32:9, and later, Pesukim 13 & 14.
And that is precisely what Yonah was worried about - that the people of Ninveh would do Teshuvah, because Nochrim are quick to change their ways but not Yisrael who are set in their ways and do not listen to the Nevi'im. See Oznayim la'Torah who elaborates and who points out that the same applies for the better - that once Yisrael get used to following Hashem, nothing can make them change their ways. Refer to Sh'mos, 34:9:1:6.
Why does the Torah juxtapose the death of Aharon to the breaking of the Luchos?
