عثمان بن عفان
Omar's swift imposition of justice against his governors for misdeeds made even powerful governors such as Muawiyah scared of him. Ali ibn Abu Talib, during the later rule of Uthman ibn Affan, wanted Uthman to be more strict with his governors, saying, "I adjure you by God, do you know that Mu'awiyah was more afraid of Omar than was Omar's own servant Yarfa?"