Isaiah 23:7

The reference is of course to Tyre, the principal subject of the prophecy.

whose antiquity … days Next to Zidon, Tyre was regarded as the most ancient city of Phœnicia. Her priests claimed for their temple the fabulous antiquity of 2300 years in the time of Herodotus (II. 44); Josephus dates the city's foundation 240 years before the building of Solomon's Temple (Ant.viii. 3, 1).

her own feet shall carry her Render: whose feet used to carry her.… The reference is not to the future captivity or flight of the Tyrians (for which the expressions are unsuitable) but to the long journeys and residence in foreign parts of her enterprising merchants.