Sahih Muslim , Book 36, Hadith 217 (In-Book) ⓘ
Through another chain of transmitters, Sa'id b. Zaid b. 'Amr reported: I heard Allah's Apostle as saying: Truffles are a kind of 'Manna' and their juice is a medicine for the eyes.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ الْمَلِكِ بْنِ، عُمَيْرٍ قَالَ سَمِعْتُ عَمْرَو بْنَ حُرَيْثٍ، قَالَ سَمِعْتُ سَعِيدَ بْنَ زَيْدٍ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " الْكَمْأَةُ مِنَ الْمَنِّ وَمَاؤُهَا شِفَاءٌ لِلْعَيْنِ " .
also referenced under: Hadith 2049 (Reference) & Book 23, Hadith 5084 (USC-MSA)