Why does the Torah write "Mishp'chos B'nei K'has" (and not 'Mishp'chos ha'Kehasi' - like it did by Gershon, in Pasuk 23)?
Sifsei Chachamim: Because they sinned and caused others to sin 1 - by the rebellion of Korach, who was from K'has - and were therefore not worthy of having a 'Hey' and a 'Yud' (of Hashem's name) 2 added to their name. 3
Malbim: Because not all of them encamped there, seeing as Moshe and the Kohanim encamped in the east.
Rashi: Based on the principle 'Oy le'Rasha, Oy li'Shecheino!' Dasan and Aviram and the two hundred and fifty men, most of them from the tribe of Reuven, who were encamped next to Korach in the south, were drawn after him and joined him in his rebellion. See also Rashi 16:1, DH 've'Dasan va'Aviram'
The Torah writess "ha'Kehasi" in Pesukim 27 and 30, and it omits the 'Hey' and the 'Yud' only here, where it states where they encamped, to hint that the omission is due to drawing B'nei Reuven into the rebellion. ? PF
Then why, in Pasuk 35, did the Torah write "le'Mishp'chos Merari", and not ha'Merari? (EC). .