Valmiki Ramayana Yuddha Kanda Sarga 83 Shloka 22

राघव Raghava, पापकर्माणः sinful actions, अधर्मेण through unrighteous means, वध्यन्तेयदि if kills, वधकर्महतः by this action of killing, सःअधर्मः that adharma, हतः of killing, कम् whom, वधिष्यतिwill be destroy

"Righteousness and unrighteousness are forms of actions, sinful or not sinful. If sinful action is unrighteous, those who have done sinful actions should suffer. Since sinful action is momentary, and as soon as the action is over unrighteousness is also gone. That being so how can unrighteousness cause pain to anyone?"