Sayyiduna Anas (may Allah be pleased with him) said that al-Zubayr and Abd al-Rahman bin Awf (may Allah be pleased with them both) both complained to the Prophet (peace and blessings be upon him) of lice during a campaign, so the Prophet (peace and blessings be upon him) permitted them to wear silk shirts. Anas (may Allah be pleased with him) said: I saw silk shirts on them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخوف / 6072
Abu Umar said: I saw with Asma' bint Abi Bakr (may Allah be pleased with her) a shirt fastened with silk buttons. She said: "The Prophet (peace and blessings be upon him) used to wear this in battle."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخوف / 6073