What does Isaiah 23:4 mean?

Be ashamed, Sidon, for the sea, the fortress of the sea, has spoken: 'I have not been in labor or given birth; I have not raised young men or brought up young women.' Isaiah 23:4 - Modern Text Bible

(Sidon, Tyre’s neighbor, is told to feel shame. The sea, which gave Tyre its power, now says it has produced nothing—no future, no hope.)