When Sa’d bin Abee Waqqaas heard about the murder of ‘Uthmaan, he said: “May Allaah have mercy upon ‘Uthmaan!” Then he recited:
“Say: ‘Shall We tell you the greatest of losers in respect of (their) deeds?’ Those whose efforts have been wasted in this life while they thought that they were acquiring good by their deeds. They are those who deny the aayaat of their Lord and the Meeting with Him (in the Hereafter). So ther works are in vain, and on the Day of Resurrection, We shall assign no weight for them. That shall be their recompense, Hell, because they disbelieved and took My aayaat and My Messengers by way of jest and mockery.” [Soorah al-Kahf: 103-106]
Then Sa’d said, “Oh Allaah! Make them regret it and make them grieve, humiliate them, then sieze them!”
[Taareekh at-Tabaree: 5/407]
Allaah answered the du’aa’ of Sa’d – who was a man whose prayers were answered – and Allaah seized everyone who had taken part in the murder of ‘Uthmaan, such as ‘Abdullaah bin Saba’, al-Ghaafiqee, al-Ashtar, Hakeem bin Jablah, and Kinaanah at-Tajeebee, as they were all killed later on.
[al-Khulafaa' ar-Raashidoon: 192]