Hisn al-Muslim · Book 1 · Hadith 139
اللَّهُمَّ لاَ سَهْلَ إِلاَّ مَا جَعَلْتَهُ سَهْلاً، وَأَنْتَ تَجْعَلُ الْحَزْنَ إِذَا شِئْتَ سَهْلاً
Allāhumma lā saḥla illā ma ja`altahu saḥla wa anta taj`alu ‘l-ḥazna idhā shi'ta saḥla. O Allah, there is no ease other than what You make easy. If You please You ease sorrow. Reference: Ibn Hibban in his Sahih (no. 24…