The King James Bible addresses mercy in several passages:
Lamentations 3:22-23 (KJV)
22 It is of the LORD’s mercies that we are not consumed, because his compassions fail not. 23 They are new every morning: great is thy faithfulness.
Matthew 5:7 (KJV)
7 Blessed are the merciful: for they shall obtain mercy.
Ephesians 2:4-5 (KJV)
4 But God, who is rich in mercy, for his great love wherewith he loved us, 5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;)
Titus 3:5 (KJV)
5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;
Micah 6:8 (KJV)
8 He hath shewed thee, O man, what is good; and what doth the LORD require of thee, but to do justly, and to love mercy, and to walk humbly with thy God?