(28) باب فَضْلِ الْكَمْأَةِ وَمُدَاوَاةِ الْعَيْنِ بِهَا
Through another chain of transmitters, Sa'id b. Zaid b. 'Amr reported:
I heard Allah's Apostle (ﷺ) as saying: Truffles are a kind of 'Manna' and their juice is a medicine for the eyes.
Reference: Sahih Muslim 2049 b
In-book reference: Book 36, Hadith 217
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 5084