It is narrated from Hazrat Urwah bin Zubair that Sayyiduna Umar bin Khattab, may Allah be pleased with him, said while he was performing tawaf of the Ka'bah, to the Black Stone: You are a stone, you can neither benefit nor harm, and if I had not seen the Messenger of Allah, peace and blessings be upon him, kissing you, I would not have kissed you. Then he kissed the Black Stone.
Imam Malik, may Allah have mercy on him, said: I heard from some people of knowledge that when one touches the Yemeni Corner and raises his hand, he should place his hand on his mouth but should not kiss it.
Hadith Referenceموطا امام مالك رواية يحييٰ / كتاب الحج / 815