On one occasion, Sayyiduna Umar (may Allah be pleased with him) addressed the Black Stone and said, "You are merely a stone. If I had not seen the Prophet (peace and blessings be upon him) kissing you, I would never have kissed you." Saying this, he kissed it.
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 380
Hadith Gradingحکم دارالسلام:حديث صحيح، عروة بن الزبير والد هشام لم يدرك عمر، خ: 1597، م: 1271