“trying to figure out the yichus of a rock…”
the rock’s yichus is that Hashem made it…besides, Hashem is compared to a rock ??? ???? ????, ??? ???? ?????, etc.
Now look at that rock in a different way!
There’s a great story how Hashem puts a rock in front of all of us (difficult obstacles) which we need to “push” in order to strengthen our muscles…