The motto " "Quod dixi dixi" was used by the Dixie family of Bosworth Hall, Leicestershire, England. The crest they used was however different to the one in the book so not them.
As the initials are H.D. I would think that these are the initials of the owner of the crest and motto.
Possibly of a family named Dixie or maybe Dixon.
Fairbairn's book of crests of the families of Great Britain and Ireland by James Fairbairn, may throw some light on the origin of the crest.
John MacDonald I would expect to be another owner of the book at sometime.
Ray