Radak: Also the children must tell their children, until the last generation. Also the children born, when their Da'as develops, they will tell their children.

Malbim: Even though among these stories are testimonies about punishments of Dor ha'Midbar, Korach's congregation and the Meraglim, Hashem knows that the coming generation [will not do like them, rather,] they will go in the path of perfection. Via these testimonies of Hashem's punishments and Hashgachah, a later generation [of David and Shlomo] will rise that will guard these testimonies and not betray further.