The Prophet ﷺ said, "Truffles are part of the manna which Allah sent down upon the Children of Israil, and their juice is a cure for the eye."
حدثنا محمد بن الصباح أنبأنا سفيان بن عيينة عن عبد الملك بن عمير سمع عمرو بن حريث يقول سمعت
عن النبي ﷺ أن الكمأة من المن الذي أنزل الله على بني إسرائيل وماؤها شفاء العين
Bukhari reported it in the Book of Tafsir, chapter "We shaded you with clouds and sent down upon you," hadith 4478, and Muslim reported it in the Book of Foods, chapter on the virtue of truffles and treating the eye with them, hadith 161/2049, from the hadith of Ibn Uyayna, with the same wording.