Musnad Ahmad 1167:64

Ya'mar narrated to us, Abdullah—meaning Ibn al-Mubarak—narrated to us, he said: Ibn Lahi'ah informed us, from Khalid ibn Yazid, he said: I heard Abdullah, the freed slave of Asma, narrating that he heard Asma bint Abi Bakr saying: "I have two arm-guards of silk for al-Zubayr, which the Prophet, may Allah bless him and grant him peace, had given to him, and he would fight in them."