Sahih al-Bukhari, Book 65, Hadith 4478 (In-Book) ⓘ
Narrated Sa`id bin Zaid: Allah's Messenger 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."
حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا سُفْيَانُ، عَنْ عَبْدِ الْمَلِكِ، عَنْ عَمْرِو بْنِ حُرَيْثٍ، عَنْ سَعِيدِ بْنِ زَيْدٍ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " الْكَمْأَةُ مِنَ الْمَنِّ، وَمَاؤُهَا شِفَاءٌ لِلْعَيْنِ " .
also referenced under: Hadith 4478 (DarusSalam) & Volume 6, Book 60, Hadith 5 (USC-MSA)