318. Amīr al-mu’minīn, peace be upon him, was asked: With what did you overpower your adversaries? He answered: Whenever I confronted a person he helped me against himself.
قال السيد الرضي: يومئ بذلك إلى تمكن هيبته فى القلوب.
as-Sayyid ar-Raḍī says: Amīr al-mu’minīn is pointing out his striking of awe in the hearts. 
 The man who is over-awed by his adversary is sure to be defeated because in facing a foe physical prowess is not enough but steadfastness of heart and strength of courage is also necessary. When the adversary loses courage and feels sure that he will be defeated then he will certainly be defeated. This is what happened to the adversary of Amīr al-mu’minīn; he was so affected by his acknowledged reputation that he was sure of death, in consequence of which his spiritual power and self confidence came to an end and eventually this mental state dragged him to his death.