The Book of Pilgrimage (Kitab Al-Hajj)
Muslim :: Book 7 : Hadith 2912
Salim narrated on the authority of his father (Allah be pleased with him) that 'Umar b. al-Khattib (Allah be pleased with him) kissed (the Black Stone) and then said: By Allah, I know that you are a stone and if I were not to see Allah's Messenger (may peace be upon him) kissing you, I would not have kissed you. Harun said in his narration: A hadith like this has been transmitted to me by Zaid b. Aslam on the authority of his father Aslam.