Allāhumma lā sahl — when a task is hard

اللَّهُمَّ لاَ سَهْلَ إِلاَّ مَا جَعَلْتَهُ سَهْلاً، وَأَنْتَ تَجْعَلُ الْحَزَنَ إِذَا شِئْتَ سَهْلاً

Allāhumma lā sahla illā mā jaʿaltahu sahlā, wa anta tajʿalu al-ḥazana idhā shiʾta sahlā.

"O Allah, nothing is easy except what You have made easy. And You make what is hard — if You will — easy."