It was narrated form Anas that the Messenger of Allah said:"None of you should wish for death because of some harm that befalls him, rather he should say: 'Allahumma ahini ma kanatil-hayatu khairanli wa tawaffani idha kanatil-wafatu khairanli (O Allah, keep me alive so alive so long as life is good for me, and cause me to die when death is good for me)