Musnad Abu Ya'la al-Mawsili 252:38

Abu Bakr ibn Abi Shaybah narrated to us, Khalid ibn Makhlad narrated to us, from Musa ibn Ya'qub al-Zam'i, who said: Abu Hazim narrated to me, from Sahl ibn Sa'd, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "People will console one another after me with a consolation for me." The people used to say: "What is this?" Then, when the Messenger of Allah (peace and blessings of Allah be upon him) passed away, we met one another, and some of us were consoling others for the Messenger of Allah (peace and blessings of Allah be upon him).