...And suddenly six men came from the direction of the upper gate, which faces north, each with his battle-ax in his hand. One man among them was clothed with linen and had a writer’s inkhorn at his side. They went in and stood beside the bronze altar.
Now the glory of the God of Israel had gone up from the cherub, where it had been, to the threshold of the temple.
And He called to the man clothed with linen, who had the writer’s inkhorn at his side; and the LORD said to him, “Go through the midst of the city, through the midst of Jerusalem, and put a mark on the foreheads of the men who sigh and cry over all the abominations that are done within it.”
To the others He said in my hearing, “Go after him through the city and kill; do not let your eye spare, nor have any pity. Utterly slay old and young men, maidens and little children and women; but do not come near anyone on whom is the mark; and begin at My sanctuary.” So they began with the elders who were before the temple. Then He said to them, “Defile the temple, and fill the courts with the slain. Go out!” And they went out and killed in the city.
Ezekiel 9:2-7