Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Hard (Adverb)
Hard as being good.
—Anonymous
As hard as to shave an egg.
—Anonymous
As hard to answer as why cats love fish.
—Anonymous
Hard to climb as Parnassus.
—Anonymous
As hard to hold as an eel by the tail.
—Anonymous
As hard as for an empty sack to stand upright.
—Benjamin Franklin
Hard as death.
—Nathaniel Hawthorne
Hard to enter my belief as Dives into heaven.
—Thomas Heywood