What did Horace say?

Sometimes if I mumbled my dad would say
What did Horace say?

Apparently it comes from a radio programme during WWII. Harry Hemsley had a family programme which featured 3 children, the youngest being Horace. Being the youngest, Horace wasn't able to speak clearly and whenever he said anything, the father would have to ask one of the other two children "What did Horace say?" and the child would translate.