Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Kindness
Little acts of kindness are stowed away in the heart, like bags of lavender in a drawer, to sweeten every object around them.
—Anonymous
To do a kindness to a bad man is like sowing your seed in the sea.
—Phocylides
Kindness, like grain, increases by sowing.
—English Proverb