Sahih Muslim Book 23, Hadith Number 5085.

Chapter : Excellence of truffles and their use as a medicine for the eyes.

Sa’id b. Zaid reported: I heard Allah’s Messenger (may peace be upon him) 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.