situate at the entry of the sea - literally, plural, “entrances,” that is, ports or havens; referring to the double port of Tyre, at which vessels entered round the north and south ends of the island, so that ships could find a ready entrance from whatever point the wind might blow (compare Eze 28:2).
merchant of ... people for many isles - that is, a mercantile emporium of the peoples of many seacoasts, both from the east and from the west (Isa 23:3), “a mart of nations.”