" يحسب ما خانوك وعصوك وكذبوك وعقابك إياهم فإن كان عقابك إياهم بقدر ذنوبهم كان كفافا لا لك ولا عليك وإن كان عقابك إياهم دون ذنوبهم كان فضلا لك وإن كان عقابك إياهم فوق ذنوبهم اقتص لهم منك الفضل أما تقرأ كتاب الله: {وَنَضَعُ الْمَوَازِينَ الْقِسْطَ لِيَوْمِ الْقِيَامَةِ} الآية؟ "
The Prophet (peace and blessings be upon him) said:
"Their betrayals, disobedience and lies will be reckoned, and the punishment you gave them will also be reckoned. If your punishment was equal to their sins, it will be even, neither in your favour nor against you. If your punishment was less than their sins, it will be a surplus in your favour. And if your punishment exceeded their sins, the surplus will be taken from you in their favour. Have you not read in the Book of Allah: 'And We will set up the scales of justice for the Day of Resurrection' (to the end of the verse)?"
Hadith Referenceصحیح الجامع الصغیر / حرف الياء / 8039