I know that you are only a stone and you cannot cause harm or bring benefit. Were it not that I saw the Messenger of Allah( ﷺ )kiss you, I would not have kissed you. Then he kissed it. (Using translation from Aḥmad 381)   

إِنَّكَ حَجَرٌ لَا تَنْفَعُ وَلَا تَضُرُّ «وَلَوْلَا أَنِّي رَأَيْتُ رَسُولَ اللهِ ﷺ قَبَّلَكَ مَا قَبَّلْتُكَ» ثُمَّ قَالَ عُمَرُ رَأَيْتُ رَسُولَ اللهِ ﷺ فَعَلَ مِثْلَ ذَلِكَ