Comparisons are odious
The earliest recorded use of this phrase appears to be by John Lydgate in his Debate between the horse, goose, and sheep, circa 1440:
"Odyous of olde been comparisonis, And of comparisonis engendyrd is haterede."
It was used by several authors later, notably Cervantes, Christopher Marlowe and John Donne.
In Much Ado About Nothing, Shakespeare gave Dogberry the line 'comparisons are odorous'. It seems that he was using this ironically, knowing it to be a misuse of what would have been a well known phrase by 1599 when the play was written.
See other phrases and sayings from Shakespeare.
See also: the List of Proverbs.