مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1632
Musnad of Sa'eed bin Zaid bin 'Amr bin Nufail
It was narrated that Sa"eed bin Zaid said: I heard the Prophet (ﷺ) say: "Truffle are a kind of manna, and its water is a healing for the eyes."
Musnad Ahmad 1632Sahih (Darussalam) [ al-Bukhari (4478) and Muslim (2049)]