Sunan an-Nasa'i, Volume 6, Book 48, Hadith 5312 (DarusSalam) ⓘ
It was narrated from Anas that: The Messenger of Allah [SAW] granted a concession to 'Abdur-Rahman bin 'Awf and Az-Zubair bin Al-'Awwam allowing them to wear silken shirts because of scabies that they were suffering from.
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا عِيسَى بْنُ يُونُسَ، قَالَ حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَرْخَصَ لِعَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ وَالزُّبَيْرِ بْنِ الْعَوَّامِ فِي قُمُصِ حَرِيرٍ مِنْ حِكَّةٍ كَانَتْ بِهِمَا .
also referenced under: Hadith 5310 (Reference) & Book 48, Hadith 271 (In-Book)