Why does it say "Tiftach ha'Aretz"?
Radak: Future tense is used in place of past. The same applies to "Az Yashir Moshe" (Shemos 15:1), "Ya'asu Egel b'Chorev" (below, verse 19) and many similar verses.
Why does it say "Adas Aviram"? It does not mention an Edah with Dasan!
Malbim: Aviram had an Edah (10) of sons and daughters 1 .
Sanhedrin 1:6 learns the number of judges on a Sanhedrin from "Edah", which is at least 10. Perhaps females can be included according to the opinion that women can be judges. (PF)
Why does it not mention that Korach was swallowed?
Rashi: This is for the honor of Korach's sons 1 ; the debacle is attributed to Dasan and Aviram.
Radak #1: There was no need to mention him; it is known that he headed the feud!
Radak #2: It mentions those who helped him, for those who help a Rasha are worse than him. If others did not help him, he would not do his evil!
Radak #3, Malbim: The Torah lists Korach among those burned and those swallowed. Here he is not mentioned among either, for both apply to him.
