Hadith 4:27
Anas said he heard the Prophet declare that God who is glorious and exalted said, “When I afflict my servant in his two loved things (i.e. his eyes), and he endures patiently, I shall compensate him for them with paradise.” Bukhari transmitted it.
وَعَن أَنَسٍ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: " قَالَ اللَّهُ سُبْحَانَهُ وَتَعَالَى: إِذَا ابْتَلَيْتُ عَبْدِي بِحَبِيبَتَيْهِ ثُمَّ صَبَرَ عَوَّضْتُهُ مِنْهُمَا الْجنَّة " يُرِيد عَيْنَيْهِ. رَوَاهُ البُخَارِيّ
Original Reference: Mishkat al-Masabih 1549