"Have you, when a disaster struck you"—meaning: on the day of Uhud—"when you had struck [the enemy] with twice as much"—on the day of Badr—"[and] you said, 'From where is this?'"—meaning: from where has this come to us while we are believers and the people are polytheists? "Say, 'It is from yourselves'"—by your disobedience to the Messenger of Allah when he commanded you not to follow those who were retreating.