THE BLACK STONE H H 168 "I saw Omar son of Khattab kissing the Black Stone and I heard him say: 'I am well aware you are only a piece of rock and have no power to confer a benefit or to harm. If I had not seen the Messenger of Allah, praise and peace be upon him, kiss you I would never have kissed you.'" R 168 Bukhari and Muslim with a chain up to 'Abis son of Rabi'a who related this.
167- وعَن عابس بن رَبيعة ، قَالَ : رَأيْتُ عُمَرَ بن الخطاب رضي الله عنه يُقَبِّلُ الحَجَرَ - يَعْنِي : الأسْوَدَ - وَيَقُولُ : إني أَعْلَمُ أنَّكَ حَجَرٌ مَا تَنْفَعُ وَلاَ تَضُرُّ ، وَلَولا أنِّي رَأيْتُ رسولَ الله صلى الله عليه وآله وسلم يُقَبِّلُكَ مَا قَبَّلْتُكَ . مُتَّفَقٌ عَلَيهِ .