Musannaf Ibn Abi Shayba 27:654

Yazid ibn Harun narrated to us, he said: Hammad ibn Salamah informed us, from Thabit, from Abd al-Rahman ibn Abi Layla, who said: While the Messenger of Allah (may Allah bless him and grant him peace) was sitting, and Jibril was with him, Khadijah approached. Jibril said: "O Messenger of Allah, this is Khadijah, so convey to her peace from Allah, Blessed and Exalted is He, and from me."