Endurance and divine recompense in grief
Nahj al-Balāgha|Volume 1|Book 3|Chapter 291
يَا أَشْعَثُ، ابْنُكَ سَرَّكَ وَهُوَ بَلاَءٌ وَفِتْنَةٌ، وَحَزَنَكَ وَهُوَ ثَوَابٌ وَرَحْمَةٌ.
O’ Ash‘ath, your son (when he lived) gave you happiness while, at the same time, he was a trial and hardship and (when he died) he grieved you while, at the same time, he has proved a source of reward and mercy for you.