Late 12th century: “God’s forgiveness of his creatures’ offenses”
9th century: “reward, gift; kindness, grace, pity” from Old French mercit, merci
6th century: applied to the heavenly reward of those who show kindness to the helpless, from Church Latin
“Master Blifil fell very short of his companion in the amiable quality of mercy; but he as greatly exceeded him in one of a much higher kind, namely, in ju
stice: in which he followed both the precepts and example of Thwackum and Square; for though they would both make frequent use of
the word mercy, yet it was plain that in reality Square held it to be inconsistent with the rule of right; and Thwackum was for doing justice, and leaving mercy to heaven.” The History of Tom Jones, a Foundling by Henry Fielding
“Look this day in mercy and blessing on Thy humble people,
and graciously hear us, spare us, and have mercy upon us.” War and Peace by Leo Tolstoy
“My men have him here under their pikes, and I shall command them to kill him without mercy.” Robin Hood by J. Walker McSpadden
In social and legal context, mercy refers to compassionate behavior coming from those in positions of power and control.
It is also commonly used in religious context, especially as a characteristic of a god or deity.