A.T. Robertson Commentary Revelation 21:13

"on the east were three gates; and on the north three gates; and on the south three gates; and on the west three gates." — Revelation 21:13 (ASV)

Three gates (πυλωνες τρεις) on each of the four sides as in Eze 42:16ff.; "on the east" (απο ανατολης, as in 16:12, starting from the east), "on the north" (απο βορρα, from the north, as in Lu 13:29), "on the south" (απο νοτου, from the south, as in Lu 13:29), "on the west" (απο δυσμων, from the west, as in Mt 8:11).