I see the city in the hand, and the hand in the stars. The tower guards the gate, but the gate holds the key. The king is the key, and the hand guards the king.
Madness string 3699
In biblical days, the way to atone for your sins was the sacrifice on the altar to God. What people don't remember now is that the altar doesn't get cleaned afterwards. So with every sacrifice, the altar gets bloodier and bloodier. It's basically a reminder of every transgression and you can't go back to the unclean state.