Frank J. Wilstach, comp. A Dictionary of Similes. 1916.
Mercy
As freely as the firmament embraces the world, so mercy must encircle friend and foe.
—Friedrich von Schiller
The quality of mercy is not strained.
It droppeth, as the gentle rain from heaven
Upon the place beneath: it is twice blessed;
It blesseth him that gives, and him that takes.
—William Shakespeare
Mercy is like a rainbow, we must never look for it after dark.
—Samuel Squire