Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Admonition
The admonition of a true friend should be like the practice of a wise physician, who wrappeth his sharp pills in fine sugar; or the cunning Chirurgeon, who lancing a wound with an iron, immediately applieth to it soft lint; or as mothers deal with their children for worms, who put their bitter seeds into sweet raisins. If this order had been observed in thy discourse, that interlacing sour taunts with sugared counsel, bearing as well a gentle rein as using a hard snaffle, than mightest have done more with the whisk of a wand, that now thou canst with a pick of the spur, and avoid that which now thou mayest not, extreme unkindness. But thou art like that kind of judge which Propertius noeth, who condemning his friend, cause him for the more ease to be hanged with a silken twist. And thou, like a friend, cuttest my throat with a razor, not with a hatchet, for my more honour.
—John Lyly