Why does the Torah write about Moshe "Vayivku B'nei Yisrael... " and about Aharon (in Bamidbar 20:29), "Kol Beis Yisrael"?
Rashi: "Kol Beis Yisrael" incorporates the women as well -who also wept when Aharon died, because he pursued Shalom. He would go out of his way to make peace between man and man and between husband and wife.
Oznayim la'Torah #1: Beause Moshe taught Yisrael the Mitzvos - what to do and what not to do, and inevitably there would sometimes have been people who would not readily have accepted his instructions 1 and who not hve wept at his death. Aharon on the other hand, atoned for the sins of the people, and it is not surprising that everybody loved him.
Oznayim la'Torah #2 (citing the Sifra in Shemini): Not everyone wept when Moshe died because he tended to rebuke them when they sinned.
Like we find in Bamidbar 11:10 "Va'yishma Moshe es ha'Am Bocheh le'Mishpechosav" - because Arayos were forbidden to them. See Oznayim la'Torah who cites other examples.
When did the days of mourning end?
Targum Yonasan: They ended on the eighth of Nisan, on the ninth they adorned their animals in preparation of the crossing of the Yarden, on the tenth they crossed the Yarden and the Manna stopped falling on the sixteenth of Nisan. 1
Targum Yonasan: It transpires that, after his death, they ate the Manna on the merit of Moshe for thirty-seven days. Rashi in Sh'mos 16:36 states that it stopped falling on the day that Moshe died. In sny event, the last day's Manna lasted until the fifteenth of Nisan. R. Yehoshua in the Mechilta and Targum Yonasan there say that they ate the Manna for forty days after his death. Refer to Sh'mos 16:36:1:1*.
What is the significance of the thirty days of weeping?
Kesuvos, 103b: It teaches us that thirty days is the maximum that one should weep over a Meis. 1
See Torah Temimah, citing Kesuvos Ibid. and note 22.
Why does the Torah insert the (otherwise superfluous) phrase "Vayitmu Y'mei Eivel Moshe"?
Seforno: Because the Pasuk continues "vi'Yehoshua bin Nun Malei Chochmah", and when people are mourning, 'there is no Chochmah and no Tevumah'.
What is the significance of the thirty days of mourning that they mourned Moshe?
Divrei Eliyahu: If not for 'the episode of Mei Merivah, Moshe and Aharon would not due to die. Moshe was considered the 'Terumah' of the world', which is six thousand years old, nd anaverage Terumah is one part in fifty = a hundred and twenty years. 1 If not for Mei Merivah however, Moshe would have been a generous Terumah (one part in forty) = a hundred and fifty years. It transpires that he lost thirty years of his life. B'nei Yisrael therefore cried for thirty years - one day for each year that he lost. 2 .
In the Pasuk in Bereishis 6:3 " ... be'Shagam Hu Basar, Vehayu Yamav Me'ah ve'Esrim Shanah"
