Surah As-Sajdah — Ayah 17 (32:17)
فَلَا تَعۡلَمُ نَفۡسٞ مَّآ أُخۡفِيَ لَهُم مِّن قُرَّةِ أَعۡيُنٖ جَزَآءَۢ بِمَا كَانُواْ يَعۡمَلُونَ ١٧
English translation (Saheeh International)
And no soul knows what has been hidden for them of comfort for eyes [i.e., satisfaction] as reward for what they used to do.
Brief commentary
So no one knows what things Allah has prepared for it in terms of bringing coolness and joy to the eyes, as a reward for the good deeds it would do in the world. It is a reward that no one except Allah can comprehend, due to its greatness.