Sunan Ibn Majah Book 34, Hadith 18
Prophet saas used to seek refuge with Allah from cowardice, miserliness, old age, the torment of the grave and the tribulation of the heart. (Da'if)(One of the narrators) Waki' said: "Meaning when a man dies in a state of tribulation (Fitnah) and does not ask Allah to forgive him."
the Messenger of Allah said: "Ask Allah for beneficial knowledge and seek refuge with Allah from knowledge that is of no benefit."
when a man had come to the Messenger of Allah (saas), he heard him say: "O Messenger of Allah, what should I say when I ask of Allah?" He said: "Say: Allahumma-ghfirli warhamni wa 'afini warzuqni (O Allah, forgive me, have mercy on me, keep me safe and sound and grant me provision)," and he held up his four fingers apart from the thumb and said: "These combine your religious and worldly affairs."