What is "Ki Eineichem ha'Ro'os" referring to? What message is the Torah conveying here?
Rashi: It is referring to "Ki Lo es Beneichem asher Lo Yad'u ... " in Pasuk 2.
Seforno: With reference to Hashem's punishing all those who rebelled against Him, 1 - Par'oh and the Egyptians in Egypt and at the Yam-Suf, and to those who rebelled in the desert, predominantly Dasan and Aviram, the Torah is instructing those who witnessed these episodes to warn their children, who did not see them, not to follow in their footsteps. 2