كتاب الجنائز
Read the English translation first, with the original Arabic directly underneath.
It was narrated that Anas said:
"The Messenger of Allah said: 'None of you should wish for death because of some harm that befalls him. If he must wish for death, let him say: Allahumma ahini ma kanatil-hayatu khairantli wa tawaffani idha kanatil-wafatu khairanli (O Allah, keep me alive so long as life is good for me, and cause me to die when death is good for me)"
أَلاَ لاَ يَتَمَنَّى أَحَدُكُمُ الْمَوْتَ لِضُرٍّ نَزَلَ بِهِ فَإِنْ كَانَ لاَ بُدَّ مُتَمَنِّيًا الْمَوْتَ فَلْيَقُلِ اللَّهُمَّ أَحْيِنِي مَا كَانَتِ الْحَيَاةُ خَيْرًا لِي وَتَوَفَّنِي إِذَا كَانَتِ الْوَفَاةُ خَيْرًا لِي