(28) باب فَضْلِ الْكَمْأَةِ وَمُدَاوَاةِ الْعَيْنِ بِهَا
Sa'id b. Zaid reported Allah's Messenger (ﷺ) as saying:
Truffles are 'Manna' which Allah, the Exalted the Majestic, sent to the people of Israil, and its juice is a medicine for the eyes.
Reference: Sahih Muslim 2049 f
In-book reference: Book 36, Hadith 221
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 5088