Translation:

118. "If Thou dost punish them they are Thy servants: if Thou dost forgive them Thou art the Exalted the Wise.

Notes (Tafseer)

832. A Master can justly punish His servants for disobedience: no one can say Him nay, for He is high above all. But if He chooses to forgive. He in His wisdom sees things that we mortals cannot see. This is the limit of intercession that men of God can make on behalf of sinners.