Musnad Ahmad 2:50

'Affan narrated to us, Wuhayb narrated to us, 'Abdullah ibn 'Uthman ibn Khuthaym narrated to us, from Sa'id ibn Jubayr, from Ibn 'Abbas: That 'Umar ibn al-Khattab leaned over the Corner (the Black Stone) and said: "I know for certain that you are a stone; and had I not seen my beloved, may Allah bless him and grant him peace, kiss you and touch you, I would not have touched you nor kissed you." "There has certainly been for you in the Messenger of Allah an excellent pattern."