Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 163
Narrated Said Ibn Zaid:
The Prophet said, "Al-Kam'a is like the Mann (sweet resin or gum) (in that it grows naturally without human care) and its water is a cure for the eye diseases."