Narrated Said bin Zaid:
Allah's Apostle ﷺ said, "The Kam'a (i.e. a kind of edible fungus) is like the Manna (in that it is obtained without effort) and its water is a (medicine) cure for eye trouble."
Sahih al-Bukhari, Vol. 6, Book of Prophetic Commentary on the Qur'an, Hadith 5
Sahih al-Bukhari, Book of Prophetic Commentary on the Qur'an, Hadith 5