Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Unkind
Unkind as fate.
—Anonymous
Unkind as hail.
—Ambrose Philips
Blow, blow, thou winter wind,
Thou art not so unkind
As man’s ingratitude.
—William Shakespeare
As winter’s frost unkind.
—Tobias Smollett