the Messenger of Allah forbade Mulamasah, which means touching a garment without looking at it, and Munabadha, which is where one man sells his garment to another man, by throwing it to him, without him checking it or looking at it.  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الْمُلاَمَسَةِ لَمْسِ الثَّوْبِ لاَ يَنْظُرُ إِلَيْهِ وَعَنِ الْمُنَابَذَةِ وَهِيَ طَرْحُ الرَّجُلِ ثَوْبَهُ إِلَى الرَّجُلِ بِالْبَيْعِ قَبْلَ أَنْ يُقَلِّبَهُ أَوْ يَنْظُرَ إِلَيْهِ