Musnad Abu Ya'la al-Mawsili 115:39

Hadaba narrated to us, Hammam narrated to us, Qatada narrated to us, from Anas, that al-Zubayr ibn al-Awwam and Abd al-Rahman ibn Awf complained to the Prophet about lice. So he granted them a concession to wear silk shirts. I saw each one of them wearing a silk shirt.