Albert Barnes Commentary 2 Kings 11:14

"and she looked, and, behold, the king stood by the pillar, as the manner was, and the captains and the trumpets by the king; and all the people of the land rejoiced, and blew trumpets. Then Athaliah rent her clothes, and cried, Treason! treason!" — 2 Kings 11:14 (ASV)

By a pillar - Rather, “upon the pillar,” probably a sort of stand or pulpit raised on a pillar. Under the later monarchy, the Jewish king seems to have had a special place assigned to him in the temple court, from which he addressed the people on occasion (see marginal references).