Sahih Muslim Book 7, Hadith Number 2914.

Chapter : Excellence of kissing the black stone ;while circumambulating.

Abdullah b. Sarjis reported: I saw the bald one, i.e. ‘Umar b. Khattab (Allah be pleased with him), kissing the Stone and saying: By Allah. I am kissing with full consciousness of the fact that you are a stone and that you can neither do any harm nor good; and if I had not seen Allah’s Messenger (may peace be upon him) kissing you. I would not have kissed you. The rest of the Hadith is the same.