Charles Ellicott Commentary Isaiah 23:7

"Is this your joyous [city], whose antiquity is of ancient days, whose feet carried her afar off to sojourn?" — Isaiah 23:7 (ASV)

Is this your joyous city ...? —Tyre was, as has been said, of later origin than Sidon, but was the oldest of the daughter cities. Josephus (Antiquities 8.3.1) fixes the date of its foundation at 240 years before Solomon.

Her own feet shall carry her. —The English version (tenable grammatically) points to the wanderings of exile. Another rendering, her feet are used to carry her ... is also legitimate, and fits in better with the context, which paints the past glory of Tyre in contrast with her coming calamities. So taken, the words point to her numerous colonies, of which Carthage was the chief.