وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ الْعَلاَءِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِيهِ، أَنَّهُ قَالَ سَأَلْتُ أَبَا سَعِيدٍ الْخُدْرِيَّ عَنِ الإِزَارِ، فَقَالَ أَنَا أُخْبِرُكَ بِعِلْمٍ، سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ إِزْرَةُ الْمُؤْمِنِ إِلَى أَنْصَافِ سَاقَيْهِ لاَ جُنَاحَ عَلَيْهِ فِيمَا بَيْنَهُ وَبَيْنَ الْكَعْبَيْنِ مَا أَسْفَلَ مِنْ ذَلِكَ فَفِي النَّارِ مَا أَسْفَلَ مِنْ ذَلِكَ فَفِي النَّارِ لاَ يَنْظُرُ اللَّهُ يَوْمَ الْقِيَامَةِ إِلَى مَنْ جَرَّ إِزَارَهُ بَطَرًا ‏"‏ ‏.‏

Yahya related to me from Malik from al Ala ibn Abd ar-Rahman thathis 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 heardthe Messenger of Allah, may Allah bless him and grant him peace, say,'The lower garment of the mumin should reach to the middle of hiscalves. There is no harm in what is between that and the ankles. Whatis lower than that is in the Fire. What is lower than that is in theFire. On the Day of Rising, Allah will not look at a person who trailshis lower garment in arrogance.' " Translation Not Available

Book Ref: Muwatta Imam Malik Book 48 Hadith 1666
Web Ref:  Muwatta Imam Malik Book 48 Hadith 12