The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness (Kitab Al-Dhikr)
Muslim :: Book 35 : Hadith 6555
This hadith has been narrated on the authority of Ubaidullah b. Umar with the same chain of transmitters and he said: Then utter:" My Lord. with Thine name I place my side and if Thou keepest me alive have mercy upon myself"