standing
The position of the Lord (Adonai) is significant. The altar speaks properly of mercy because of judgement executed upon an interposed sacrifice, but when altar and sacrifice are despised the altar becomes a place of judgment.
Compare (John 12:31).
1 I saw the Lord standing upon the altar: and he said, Smite the lintel of the door, that the posts may shake: and cut them in the head, all of them; and I will slay the last of them with the sword: he that fleeth of them shall not flee away, and he that escapeth of them shall not be delivered.