اَللَّهُمَّ أَحْيِنِيْ مَا كَانَتِ الْحَيَاةُ خَيْرًا لِّيْ، وَتَوَفَّنِيْ إِذَا كَانَتِ الْوَفَاةُ خَيْرًا لِّيْ

Allaahumma ahyinee maa kaanatil hayaatu khayran lee, wa tawaffanee idhaa kaanatil wafaatu khayran lee.

O Allah! Keep me alive as long as life is better for me, and let me die if death is better for me.

Reference: Bukhari: 5671