Musnad Ahmad Hadith 5486

Thabit Banani, may Allah have mercy on him, says that once I asked Ibn Umar, may Allah be pleased with them both, whether the use of nabidh (fermented drink) in earthen pots was prohibited. He replied: "That is what they say." I asked, "Who says this?" He replied: "That is what they say." I asked the same question again, and he gave the same answer. Allah saved me from him that day, because when someone would ask him, "Did you really hear this from the Prophet (ﷺ)?" he would become angry and turn his attention to that person.