When the Babylonians breached the walls of Jerusalem and stormed the Temple, they found something in the courtyard that stopped them cold. A pool of blood. Bubbling. Boiling. Churning as though it were alive — and it had been doing this for centuries.
This was the blood of Zechariah the prophet, son of Jehoiada the priest, who had been murdered in the Temple courtyard by order of King Joash (2 Chronicles 24:20-22). Zechariah had rebuked the king for abandoning God, and the king had him stoned to death — in the very courtyard of the Temple itself. As Zechariah lay dying, he cried out: "May the Lord see and avenge!"
God saw. And the blood refused to be silent. According to the Talmud in Gittin (57b) and multiple midrash (rabbinic interpretive commentary)ic sources including Pesikta Rabbati (chapter 25) and Lamentations Rabbah, the blood of Zechariah continued to boil on the Temple floor for over two hundred years. No amount of washing could clean it. No amount of time could cool it. It was a wound in the earth itself, a permanent accusation against a nation that had murdered its own prophet in the house of God.
When the Babylonian general Nebuzaradan entered the Temple and saw the boiling blood, he demanded an explanation. The Jews tried to cover it up — it was the blood of sacrificial animals, they said. Nebuzaradan was not convinced. He slaughtered animals and compared the blood. It was different. He pressed harder. Finally, the truth came out.
The general turned to the boiling blood. "I will appease you," he said, and began killing Jews over the blood until it finally grew still. The rabbis preserved this horrifying tale as a lesson: innocent blood cries out from the ground, and its cry does not fade with time.