Sahih Bukhari
Sahih Bukhari Volume 002, Book 026, Hadith Number 667.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 26. Pilgrimmage (Hajj)
Narated By 'Abis bin Rabia : 'Umar came near the Black Stone and kissed it and said "No doubt, I know that you are a stone and can neither benefit anyone nor harm anyone. Had I not seen Allah's Apostle kissing you I would not have kissed you."