(Verse 4-5) Blush, Sidon, said the sea; but the strength of the sea says, I have not given birth, nor have I brought forth, nor have I nourished young men, nor have I exalted virgins. But when it is heard in Egypt, sorrow will seize them over Tyre. The sea of this age, in which small creatures dwell with large ones, and the dragon which God created to mock it, seeing the hunters of Christ, who hunt from every mountain and hill, captured those who had been previously captured by demons, speaks to the opposing strength of the hunters, which is interpreted as Sidon, and says to it: Blush, Sidon; for I have not given birth, nor have I brought forth, nor have I nourished young men captured by you, nor have I exalted virgins, whose foolishness is condemned in the Gospel (Matthew 25). For by my travail, and travail, and nourishing, and the raising of virgins, is the travail of the Apostles of Christ abolished; of whom one spoke: My little children, of whom I travail in birth again until Christ be formed in you (Gal. IV, 19). And: I have given you milk to drink, not meat (I Cor. III, 2). And again: But I would have you to be without solicitude. He that is without a wife is solicitous for the things that belong to the Lord, how he may please God. But he that is with a wife is solicitous for the things of the world, how he may please his wife: and he is divided (I Cor. VII, 32-34). Also: Woman is saved by bearing children, if she continue in faith, and love, and sanctification, with sobriety (I Tim. II, 15). When Egypt shall hear this, which is called in Hebrew Mesraim, which is interpreted as pressing out, that is, afflicting, and oppressing, she shall be disturbed, understanding that she herself shall suffer the same things that Tyre endured. And when it is referred to all vices, it can be understood in the diversity of heresies, when one captivates through heresy, another trembles, and in the confusion of one, another feels that it must be captured. However, as it is said about Sodom: For if the miracles that were done in you had been done in Sodom, it would have remained until this day; and it is inferred: Nevertheless, it will be more tolerable for Sodom on the day of judgment than for you: thus we learn about Tyre and Sidon from the Savior saying: Nevertheless, it will be lighter for Tyre and Sidon on the day of judgment than for that city (Matthew 11:21 ff.). Now the Canaanite woman, who understood that her daughter, that is, her soul, was being severely vexed by a most fierce demon, is said to have come out from the borders of Tyre and Sidon. For she could not encounter the Savior otherwise, unless she had left the borders of Tyre and Sidon.
(Verse 5) When it is heard in Egypt, they will grieve when they hear about Tyre. This is clear, that after the Egyptians hear about the most powerful and neighboring nation being destroyed by a long siege, they will also know that their own destruction is approaching.
[AD 420] Jerome on Isaiah 23:4-5