Sahih Muslim Book 7, Hadith Number 2915.

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

Abas b. Rabi’a reported: I saw ‘Umar (Allah be pleased with him) kissing the Stone and saying: I am kissing you and I know that you are a stone. And if I had not seen Allah’s Messenger (may peace be upon him) kissing you, I would not have kissed you.