Sunan an-Nasai Book 50, Hadith 5512

أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ طَاوُسٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُعَلِّمُهُمْ هَذَا الدُّعَاءَ كَمَا يُعَلِّمُ السُّورَةَ مِنَ الْقُرْآنِ ‏ "‏ قُولُوا اللَّهُمَّ إِنَّا نَعُوذُ بِكَ مِنْ عَذَابِ جَهَنَّمَ وَأَعُوذُ بِكَ مِنْ عَذَابِ الْقَبْرِ وَأَعُوذُ بِكَ مِنْ فِتْنَةِ الْمَسِيحِ الدَّجَّالِ وَأَعُوذُ بِكَ مِنْ فِتْنَةِ الْمَحْيَا وَالْمَمَاتِ ‏"‏ ‏.‏

It was narrated from 'Abdullah bin 'Abbas that:The Messenger of Allah [SAW] used to teach them this supplication as he would teach them a Surah of the Qur'an: "Say: 'Allahumma, inni na'uwdhu bika min 'adhabi jahannama, wa a'udhu bika min 'adhabil-qabri, wa a'udhu bika min fitnatil-masihid-dajjali, wa a'udhu bika min fitnatil-mahya wal-mamat (O Allah, we seek refuge with You from the torment of Hell, and I seek refuge with You from the torment of the grave, and I seek refuge with You from the tribulation of Al-Masihid-Dajjal, and I seek refuge with You from the trials of life and death)