He used to kiss the stone and say, "I am kissing you, and I know that you are only a stone. Had I not seen the Messenger of Allah ﷺ kiss you, I would not kiss you."
حدثنا هناد حدثنا أبو معاوية عن الأعمش عن إبراهيم عن عابس بن ربيعة قال
يقبل الحجر ويقول إني أقبلك وأعلم أنك حجر ولولا أني رأيت رسول الله ﷺ يقبلك لم أقبلك
Agreed upon (by Bukhari and Muslim). Muslim narrated it in the Book of Hajj, chapter on the recommendation of kissing the Black Stone during tawaf, no. 1270, from the hadith of Abu Muawiya al-Darir, and Bukhari narrated it in the Book of Hajj, chapter on what has been mentioned regarding the Black Stone, no. 1597, from the hadith of Amash with the same wording.There is also a report on this topic from Abu Bakr [Daraqutni in al-Ilal al-Waridah: 1/167] and Ibn Umar [to come: 861].