Verses with the word unmerciful in the Apocrypha (2 verses):

Sirach 35:18
For the Lord will not be slack, neither will the Mighty be patient toward them, till he have smitten in sunder the loins of the unmerciful, and repayed vengeance to the heathen; till he have taken away the multitude of the proud, and broken the sceptre of the unrighteous;

Sirach 37:11
Neither consult with a woman touching her of whom she is jealous; neither with a coward in matters of war; nor with a merchant concerning exchange; nor with a buyer of selling; nor with an envious man of thankfulness; nor with an unmerciful man touching kindness; nor with the slothful for any work; nor with an hireling for a year of finishing work; nor with an idle servant of much business: hearken not unto these in any matter of counsel.