Tell your children and your children their children, and their children another generation.
Joel 1:3
Sometimes, for various reasons, children and parents disconnect from each other when the children grow up. It is very unfortunate because it is important for children to glean from their parents a good understanding of the past and their perspective on the future. In the past, people understood the importance of this, but in our modern world we have often entrusted this to the public at large.
Joel is telling his readers that this message would be something to pass down. It was not simply meant to be understood as a tale to share. It would be a guide and resource for generations to come.