Adam Clarke on Isaiah 29:21

Him that reproveth in the gate "Him that pleaded in the gate" - "They are heard by the treasurer, master of the horse, and other principal officers of the regency of Algiers, who sit constantly in the gate of the palace for that purpose:" that is, the distribution of justice. - Shaw's Travels, p. 315, fol. He adds in the note, "That we read of the elders in the gate. Deu 21:15; Deu 25:7; and, Isa 29:21; Amo 5:10, of him that reproveth and rebuketh in the gate. The Ottoman court likewise seems to have been called the Porte, from the distribution of justice and the dispatch of public business that is carried on in the gates of it."