Muwatta Malik 1663

Yahya related to me from Malik from al Ala ibn Abd ar-Rahman that his father said, "I asked Abu Said al-Khudri about the lower garment. He said that he would inform me with knowledge and that he had heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'The lower garment of the mumin should reach to the middle of his calves. There is no harm in what is between that and the ankles. What is lower than that is in the Fire. What is lower than that is in the Fire. On the Day of Rising, Allah will not look at a person who trails his lower garment in arrogance