Ezekiel - Chapter 9
Gabriel's Pen
G-d called loudly that those appointed over the destruction of Jerusalem should come near, bringing their weapons. (Presumably, this refers to angels of destruction, although it may also refer to the Babylonian generals. For our purposes, we will go with the explanation that it refers to angels.) Six armed men (angels) came from the northeast gate of the Temple, plus a seventh man (angel) in white linen. (Tradition tells us that this was Gabriel, who matches this description in the Book of Daniel.) The man in linen had a scribe's tablet across his hip. The group stood by the altar.
G-d told the man with the tablet to go through the city and mark a sign - apparently the letter "tav" - on the forehead of all those who agonize over the abominations that have been done. The others were to follow him and strike down all those not so marked. They were to start with the idolators at the Temple, so they began with the elders of the secret room (from the previous chapter). G-d told the angels not to be concerned with the general prohibition of a corpse in the Temple, as the people had already defiled the place pretty thoroughly with their idols. So the angels started smiting.
While they were out striking people down, Ezekiel was left alone and he started crying, "G-d, will You destroy the entire people in Your wrath?" G-d replied that the sin of the people was very great - the land was full of blood and the city was full of injustice. The people reasoned that G-d didn't care what they did. Because of this, He would not have mercy on them. Then, the figure in linen returned and reported that he had finished marking the people.