Ezekiel 9:4, 6

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.”

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.