The most capable of pardoning is the most powerful to punish
Nahj al-Balāgha|Volume 1|Book 3|Chapter 52
٥٢. وَقَالَ (عليه السلام): أَوْلَى النَّاسِ بِالْعَفْوِ أَقْدَرُهُمْ عَلَى الْعُقُوبَةِ.
52. Amīr al-mu’minīn, peace be upon him, said: The most capable of pardoning is he who is the most powerful to punish.