>>216172182
It's a historical artifact with some religious significance to Islam, as it represents God's covenant with man.
In Islamic theology, it came down to Abraham (our patriarch) and his two sons, Ismael and Isaac as a clear beautiful white stone, that eventually become opaque black, symbolising humanity (Adam's) sin.
kissing or even touching the rock is not a part of the pilgrimage to Kaaba. It's a mere museum piece, an igneous rock, that's been shattered, stolen, put together & lost again countless times. But people still do it in veneration of the holiest site in Islam. Like they would kiss the ground, the walls, or anything.
(and because muhammad did it that one time, so one of the Caliphs did it too).
Its connection to muhammad himself is just historical. He qwelled the tribal fued of the beduins, by having all of the leaders place it near the Kaaba together, as a sign of unity.