Decline and destruction of this world
Nahj al-Balāgha|Volume 1|Book 1|Chapter 64
وَاتَّقُوا اللهَ عِبَادَ اللهِ، وَبَادِرُوا آجَالَكُمْ بِأَعْمَالِكُمْ وَابْتَاعُوامَا يَبْقَى لَكُمْ بِمَا يَزُولُ عَنْكُمْ، وَتَرَحَّلُوافَقَدْ جُدَّ بِكُمْ وَاسْتَعِدُّوا لِلْمَوْتِ فَقَدْ أَظَلَّكُمْ وَكُونُوا قَوْماً صِيحَ بِهمْ فَانْتَبَهُوا، وَعَلِمُوا أَنَّ الدُّنْيَا لَيْسَتْ لَهُمْ بِدَارٍ فَاسْتَبْدَلُوا
O creatures of Allāh! Fear Allāh and anticipate your death by good actions. Purchase everlasting joy by paying transitory things — pleasures of this world. Get ready for the journey, for you are being driven, and prepare yourself for death, since it is hovering over you. Be a people who wake up when called, and who know that this world is not their abode, and so have it changed (with the next).