Zubayr bin Awwam and Abdul-Rahman bin Awf complained to the Messenger of Allah ﷺ about lice, so he granted them permission to wear silk. I saw each of them wearing a silk shirt.
حدثنا يزيد أخبرنا همام يعني ابن يحيى عن قتادة
أن الزبير بن العوام وعبد الرحمن بن عوف شكوا إلى رسول الله ﷺ القمل فرخص لهما في لبس الحرير فرأيت على كل واحد منهما قميصا من حرير
Its isnad is sahih. Bukhari related the hadith in 6/100, no. 2920, in Fath al-Bari, in the book of jihad, chapter on wearing silk in war, and Muslim in 3/1647, no. 2076, in the book of clothing, chapter on the permissibility of wearing silk for one who suffers from an ailment, and Tirmidhi in 4/218, no. 1722, in the book of clothing, chapter on what has been said about wearing silk.