Truffles are a kind of 'Manna' which Allah the Glorious and Exalted, sent down upon the people of Israil, and its juice is a medicine for the eyes.
Sahih Muslim Book 36, Hadith 219
← Previous Hadith I heard Allah's Messenger (ﷺ) as saying: Truffles are a kind of blessing and their juice is a medicine for the eyes. Shu'ba said: When Hakam narrated this hadith to me, I did not deem it as a Munkar hadith because of the narration of Abd al-Malik.

Sahih Muslim Book 36, Hadith 218 Next Hadith → Truffles are a kind of 'Manna' which Allah sent down upon Moses and their juice is a medicine for the eyes.

Sahih Muslim Book 36, Hadith 220