Musnad Ahmad 20:17

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, who said: Hisham ibn 'Urwah ibn al-Zubayr narrated to me, from his father 'Urwah, from 'Abdullah ibn Ja'far ibn Abi Talib, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "I have been commanded to give glad tidings to Khadijah of a house made of hollowed pearls, in which there is no clamor and no weariness."