It was narrated from 'Abdullah bin 'Abbas that:

The Messenger of Allah ﷺ 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.)'"

أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ طَاوُسٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ ﷺ 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 " .