Musnad Ahmad 27:641

Isma'il narrated to us, Ayyub informed us, from Sa'id ibn Jubayr, who said: I was with Ibn Umar, and he was asked about the nabidh (fermented drink) of the jar. He said: "The Messenger of Allah, may Allah bless him and grant him peace, forbade it." It weighed heavily upon me when I heard it. So I went to Ibn Abbas and said: Ibn Umar was asked about something. He said: I began to make it seem significant. He said: "And what is it?" I said: He was asked about the nabidh of the jar, and he said: "The Messenger of Allah, may Allah bless him and grant him peace, forbade it." He said: "He spoke the truth; the Messenger of Allah, may Allah bless him and grant him peace, forbade it." I said: "And what is the jar?" He said: "Everything that is made of clay."