Musnad Ahmad 1153:358

Hassan ibn Musa narrated to us, Ibn Lahi'ah narrated to us, Abu al-Aswad narrated to us, from Urwah, from Aisha, that Khadijah asked the Messenger of Allah, peace and blessings of Allah be upon him, about Waraqah ibn Nawfal. He said: "I saw him in a dream, and I saw upon him white garments. I reckon that if he were among the people of the Fire, he would not have had white garments upon him."