When sin becomes so ingrained that we stop trying to hide it, we've crossed a dangerous line. This verse reveals a heart that no longer fears God's gaze.
The act of leaving blood on a bare rock, instead of covering it, suggests Jerusalem had grown accustomed to, and even proud of, her violence and idolatry. The Law required that blood be poured out and covered—a symbolic act of respect for life and acknowledgment of the gravity of shedding blood. By contrast, Jerusalem’s actions were a public display, almost a boast. They didn't try to hide their shedding of innocent blood, indicating a profound hardness of heart and a defiance that exposed their sin 'in the midst of her' for all to see.