Musnad Abu Ya'la al-Mawsili 155:249

On the authority of Abu Hurayrah, he said: Gabriel came to the Prophet and said: "O Messenger of Allah, this is Khadijah coming to you with a vessel containing stew, or food, or drink. So when she comes to you, greet her with peace from her Lord, and give her glad tidings of a house in Paradise made of hollowed pearls, in which there is no clamor and no fatigue."