O Allah, I seek refuge in You from the punishment of the grave, and from the punishment of Hell-fire...
Reference:Al-Bukhari 2/102, Muslim 1/412, and this is Muslim's wording.Hisnul Muslim 55
اللّهُـمَّ إِنِّـي أَعـوذُ بِكَ مِـنْ عَذابِ القَـبْر وَمِـنْ عَذابِ جَهَـنَّم وَمِـنْ فِتْـنَةِ المَحْـيا وَالمَمـات وَمِـنْ شَـرِّ فِتْـنَةِ المَسيحِ الدَّجّال
Allāhumma ‘innī ‘a`ūdhu bika min `adhābi ‘l-qabri. wa min `adhābi jahannam. wa min fitnati ‘l-maḥyā wa ‘l-mamāti. wa min sharri fitnati ‘l-masīḥid-dajjāl.
O Allah, I seek refuge in You from the punishment of the grave, and from the punishment of Hell-fire, and from the trials of life and death, and from the evil of the trial of the False Messiah.