عَن أنسٍ قَالَ: كَانَ أَحَبُّ الثِّيَابِ إِلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنْ يَلْبَسَهَا الْحِبَرَةُ

Anas told that God’s messenger gave licence to az-Zubair and ‘Abd ar-Rahman b. ‘Auf to wear silk because of an itch which they had.(Bukhari and Muslim.)In a version by Muslim he said they complained of bugs and he gave them licence to wear silk shirts.