I happened to pass before Messenger of Allah (may peace be upon bin) with my lower garment trailing (upon the ground). He said: 'Abdullah, tug up your lower garment,, I tugged it up, and he again said: Tug it still further, and I tugged it still further and I went on tugging it afterward, whereupon some of the people said: To what extent? Thereupon he said: To the middle of the shanks. (Using translation from Muslim 2086)
مَرَرْتُ عَلَى رَسُولِ اللهِ ﷺ وَفِي إِزَارِي اسْتِرْخَاءٌ فَقَالَ يَا عَبْدَ اللهِ ارْفَعْ إِزَارَكَ فَرَفَعْتُهُ فَقَالَ زِدْ فَزِدْتُ فَمَا زِلْتُ أَتَحَرَّى بَعْدُ فَقَالَ بَعْضُ الْقَوْمِ أَيْنَ؟ فَقَالَ أَنْصَافَ السَّاقَيْنِ