speak evil of

References in classic literature ?
"Thee mustn't speak evil of thy rulers, Simeon," said his father, gravely.
In Ghana, it seems the Chinese can do anything at all, and when we talk we get warned by their Ambassador here, not to speak evil of her people.
If we will think about it, those who continue the hate crime, speak evil of others, condemn gay people, rejoice over the mourning of those who lost loved ones in this tragic event, also got killed, and they are not aware of their deaths.