E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Licks the Butter.
The very dogs refused to lick the butter from his forehead. Before the dead body of a Parsee is removed from the house, the forehead is smeared with clarified butter or ghee, and the dogs of the house are admitted. If the dog or dogs lick the butter, it is a good omen; if not, it signifies perdition.