Charles Ellicott Commentary Isaiah 23:4

"Be thou ashamed, O Sidon; for the sea hath spoken, the stronghold of the sea, saying, I have not travailed, nor brought forth, neither have I nourished young men, nor brought up virgins." — Isaiah 23:4 (ASV)

Be thou ashamed, O Zidon ... —Zidon is addressed as the mother-city of Tyre. The “strength” (or fortress) of the sea is the rock-island on which the new Tyre was built. She sits as a widow bereaved of her children, with no power to renew the population which once crowded her streets .