Musannaf Ibn Abi Shaybah

Hazrat Imran bin Hadeer says that I went to Abu Majliz while he was eating food. He said, "Come closer and eat food." I said, "I am fasting." Hazrat Abu Majliz said, "Perhaps you are among those people who do not fast but pretend that they are fasting!" I said, "Allah is pure." He said, "The one who was better than you used to fast three days every month and then would say, 'I am fasting.'"