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."

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 ﷺ " الْكَمْأَةُ مِنَ الْمَنِّ، وَمَاؤُهَا شِفَاءٌ لِلْعَيْنِ ".