I asked Abu Sa'id al-Khudri about wearing lower garment. He said: You have come to the man who knows it very well. The Messenger of Allah ﷺ said: The way for a believer to wear a lower garment is to have it halfway down his legs and he is guilty of no sin if it comes halfway between that and the ankles, but what comes lower than the ankles is in Hell. On the day of Resurrection. Allah will not look at him who trails his lower garment conceitedly.  

قَالَ رَسُولُ اللَّهِ ﷺ إِزْرَةُ الْمُسْلِمِ إِلَى نِصْفِ السَّاقِ وَلاَ حَرَجَ أَوْ لاَ جُنَاحَ فِيمَا بَيْنَهُ وَبَيْنَ الْكَعْبَيْنِ مَا كَانَ أَسْفَلَ مِنَ الْكَعْبَيْنِ فَهُوَ فِي النَّارِ مَنْ جَرَّ إِزَارَهُ بَطَرًا لَمْ يَنْظُرِ اللَّهُ إِلَيْهِ  

The Prophet ﷺ said: Hanging down is in lower garment, shirt and turban. If anyone trails any of them conceitedly, Allah will not look at him on the Day of Resurrection.  

عَنِ النَّبِيِّ ﷺ قَالَ الإِسْبَالُ فِي الإِزَارِ وَالْقَمِيصِ وَالْعِمَامَةِ مَنْ جَرَّ مِنْهَا شَيْئًا خُيَلاَءَ لَمْ يَنْظُرِ اللَّهُ إِلَيْهِ يَوْمَ الْقِيَامَةِ  

What the Messenger of Allah ﷺ said about lower garment also applies to shirt.  

قَالَ رَسُولُ اللَّهِ ﷺ فِي الإِزَارِ فَهُوَ فِي الْقَمِيصِ  

Why do you put on the lower garment in this way? He replied: It is how I saw the Messenger of Allah ﷺ do it.  

رَأَيْتُ رَسُولَ اللَّهِ ﷺ يَأْتَزِرُهَا