Thabit Banani, may Allah have mercy on him, says that once I asked Sayyiduna 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 again: "Is it the Prophet (peace and blessings be upon him)?" He replied: "That is what they say." I repeated the same question, and he gave the same answer. Allah saved me from him that day, because whenever someone would ask him, "Did you really hear this from the Prophet (peace and blessings be upon him)?" he would become angry and turn his attention to that person.