Grief and the transient nature of life
Nahj al-Balāgha|Volume 1|Book 3|Chapter 357
إِنَّ هذَا الْأَمْرَ لَيْسَ لَكُمْ بَدَأَ، وَلَا إِلَيْكُمُ انْتَهَى، وَقَدْ كَانَ صَاحِبُكُمْ هذَا يُسَافِرُ، فَعُدُّوهُ فِي بَعْضِ أَسْفَارِهِ، فَإِنْ قَدِمَ عَلَيْكُمْ وَإِلَّا قَدِمْتُمْ عَلَيْهِ.
This thing has not started with you nor does it end with you. This fellow of yours was used to journeying and therefore it is better to think him still to be journeying. Either he will rejoin you or else you will rejoin him.