Ibne Abbas says that "One night I went to the Masjid so that I may perform Namaz-e-Shab there. I saw Ameerul Momineen (a.s.) praying there. I sat in a corner to see the beauty of worship and listen to the recitation of Quran. Imam finished the Nafila of Shab and the Namaz-e-Shab and Vatr prayers. Then he (a.s.) recited some supplications like I have never heard. When he (a.s.) finished the prayers, I asked him: 'May I be sacrificed on you! What prayer you have recited?'" "It was Dua-e-Sanamay Quraish," he (a.s.) replied. Then he (a.s.) said, "By the One in Whose control is the life of Muhammed and Ali, one who recites this dua would be rewarded so much as if he has participated in Jehad with the Messenger of Allah (s.a.w.a.) at the Battle of Uhud and Tabuk, and he has been martyred before the eyes of the Prophet (s.a.w.a.). He would also get the reward of 100 Hajjs and Umrahs performed with the Prophet (s.a.w.a.). And the reward of fasting for 1000 months. Also on the day of Qiyamat he would be raised with the Messenger of Allah (s.a.w.a.) and the Infallible Imams and the Almighty Allah would forgive all his sins, even if they had been equal to the stars of the sky, sand particles of the desert and leaves of all the trees. Also that person would be safe from the punishment of the grave. A door of Paradise would be opened for him."
Insha Allah, all his supplications would be answered. O Ibne Abbas! If a calamity befalls one of our followers, he should recite this Dua."