It was narrated from Anas bin Malik that the Messenger of Allah ﷺ granted a concession to Zubair bin ‘Awwam and ‘Abdur-Rahman bin ‘Auf, allowing them to wear silk shirts, because of a rash they were suffering from.  

أَنَّ رَسُولَ اللَّهِ ﷺ رَخَّصَ لِلزُّبَيْرِ بْنِ الْعَوَّامِ وَلِعَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ فِي قَمِيصَيْنِ مِنْ حَرِيرٍ مِنْ وَجَعٍ كَانَ بِهِمَا حِكَّةٍ