Matilda is a novel written by Roald Dahl first published in 1988. It follows the story of a young girl, Matilda, who grows up in a very cold and sterile family environment. In order to help you answer your question, it is important to note that Dahl doesn't actually explicitly state in his work how parents should treat their children. However, the reader can still get a glimpse into Dahl's view of parenting given the negative way in which he describes Matilda's family.
The portrayal of Matilda's parents as emotionally cold and unloving indicates that Dahl thinks that this is the wrong way to be as a parent. Through the character of Matilda, the reader can see how every child needs love and craves parental affection. In Matilda's case, she does not receive this at all from her parents, and instead she finally experiences this through her teacher, Miss Honey. You could therefore argue that Dahl wants to show how a loving and warm relationship between parents and children is absolutely essential for a happy childhood. Obviously, as modern child psychologists have established, this statement is very true, therefore I strongly agree with it.
Another important message about how parents should treat their children could be seen in the fact that Matilda regularly outsmarts her parents when she plays tricks on them. Parents can often be tempted to assume that they are smarter than their children merely because of the fact that they are older. Through Matilda's pranks on her parents, however, Dahl shows the reader that this is not necessarily the case and that it is indeed possible for children to outsmart their parents. Therefore, you could use this as an argument to say that Dahl wants his readers to realize that parents should not arrogantly presume that they are smarter than their kids. Instead, like Miss Honey in the novel, parents should respect their children, realize their potential, and support their children in making the most of their talents. Again, there is no reason why I would not agree with this sentiment.