"The work of placing the mark, or seal, upon God's children entrusted to one angel." Stephen Haskell
And the glory of the God of Israel was gone up from the cherub, whereupon he was, to the threshold of the house.
And he called to the man clothed with linen,
which had the writer's inkhorn by his side;
And the LORD said unto him, Go through the midst of the city, through the midst of Jerusalem, and set a mark upon the foreheads of the men that sigh and that cry for all the abominations that be done in the midst thereof.
Ezekiel 9:3,4