Selections from The Sayings and Preaching of Amir al-Muminin Ali ibn Abi Talib (Peace Be Upon Him) Including His Replies to Questions and Maxims Expressed for Various Purposes.Translated by Sayyid Ali Reza
وَقَالَ (عليه السلام):
Amir al-mu'minin, peace be upon him, said:
أَشَدُّ الذُّنُوبِ مَا اسْتَخَفَّ بِهِ صَاحِبُهُ.
The worst sin is that which the committer takes lightly.
