It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him) used to say often: 'Subhanaka rabbana wa bihamdik' (Glory be to You, our Lord, and with Your praise). Then when this surah was revealed: "When the help of Allah and the victory come" [Surah al-Nasr: 1] , he (peace and blessings be upon him) began to say (this supplication): 'Subhanaka rabbana wa bihamdik, Allahumma ighfir li, innaka anta al-Tawwab al-Rahim' (Glory be to You, our Lord, and with Your praise; O Allah, forgive me, indeed You are the Oft-Returning, the Most Merciful). The chain of this hadith is sahih (authentic), but the two Shaykhs (Bukhari and Muslim) did not record it.