Yahya related to me from Malik from Hisham ibn Urwa from hisfather that Umar ibn al-Khattab said to the corner of the Black Stonewhile he was doing tawaf of the House, "You are only a stone, and if Ihad not seen the Messenger of Allah, may Allah bless him and grant himpeace, kiss you, I would not do so." Then he kissed it.Malik said, "I have heard some of the people of knowledge recommendingsomeone doing tawaf of the House to put his hand to his mouth when hetakes it from the Yamani corner."
USC-MSA web (English) reference: Book 20, Hadith 116
Arabic reference: Book 20, Hadith 819