Musnad Abu Ya'la al-Mawsili 2:50

Ubayd Allah ibn Umar narrated to us, Abd al-Rahman narrated to us, from Sufyan, from Ibrahim ibn Abi al-A'la, from Suwayd ibn Ghafalah, who said: I saw Umar ibn al-Khattab kissing the Stone, and he said: "Verily, I am kissing you, and I know that you are a stone that neither harms nor benefits. But I saw the Messenger of Allah, may Allah bless him and grant him peace, being affectionate toward you."