Narrated Sa`id Ibn Zaid:
The Prophet (ﷺ) 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." (DE)
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 163 (DE)
Arabic reference (DE): Book 65, Hadith 4639 (DE)