C. F. Keil and Franz Delitzsch on Joshua 6:1

Jos 6:1 “Jericho was shutting its gates (vid., Jdg 9:51), and closely shut.” The participles express the permanence of the situation, and the combination of the active and passive in the emphatic form מסגּרת (lxx συγκεκλεισμένη καὶ ὠχυρωμένη; Vulg. clausa erat atque munita) serves to strengthen the idea, to which still further emphasis is given by the clause, “no one was going out and in,” i.e., so firmly shut that no one could get out or in.