Adam Clarke on 2 Kings 11:16

By the way - which the horses came - They probably brought her out near the king's stables. It has been supposed, from Eze 46:1, Eze 46:2, that the east gate of the inner court was that by which the king entered on the Sabbath day, whereas on all other days he entered by the south gate.

And there was another gate, called the horse gate, in the wall of the city, (Jer 31:40), for the king's horses to go out at from the stables at Millo, which is therefore called, 2Chr 23:15, the horse gate toward the king's house.