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.
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 they ate the Manna on the merit of Moshe - after his death - for 37 days. Rashi, Sh'mos 16:36 says that it stopped falling when Moshe died; the last day's Manna lasted until the 115th of Nisa, R. Yehoshua in Mechilta and Targum Yonasan there say that they ate forty days after his death. Refer to Sh'mos 16:36:1:1*.
What is the significance of 30 days of mourning for Moshe?
Divrei Eliyahu: If not for Mei Merivah, it was not time for Moshe and Aharon to die. Moshe was the Terumah of the world. The world is 6000 years. Moshe was an average Terumah, one part in 50, i.e. 120 years. If not for Mei Merivah, Moshe would have been a generous Terumah (one part in 40), i.e. 150 years. He lost 30 years. Bnei Yisrael cried one day for each year lost. 1 .