(Verse 15 and following) And it shall come to pass in that day, that Tyre shall be forgotten seventy years, according to the days of one king: after the end of seventy years, Tyre shall sing as a harlot. Take a harp, go about the city, O harlot that has been forgotten; make sweet melody, sing many songs, that you may be remembered. After seventy years, the LORD will visit Tyre, and she shall return to her hire, and shall commit fornication with all the kingdoms of the world upon the face of the earth. And his merchandise shall be holy unto the Lord: it shall not be gathered nor laid up; for his merchandise shall be for them that dwell before the Lord, to eat sufficiently, and for durable clothing. This that is spoken of: a memorial before the Lord: and upon the face of the earth. And as the time of a man's life, which is not contained in the Hebrew, but is added in the Greek. And Tyre, after the seventy years of her captivity, shall return, and shall play the harlot with all the kingdoms of the world upon the face of the earth. And her merchandise and her hire shall be holiness to the Lord: it shall not be treasured nor laid up, for her merchandise shall be for them that dwell before the Lord, to eat sufficiently, and for durable clothing. The divine discourse exhorts Sidon and Tyre to repentance, and promises that his labors and rewards are to be sanctified by the Lord. Who does not have hope for salvation from sins, if indeed he has sung well, and all the strings of virtues, which were once slackened, are to be composed into praises of the Lord? We read in the forty-fourth psalm, which specifically pertains to the union of the bridegroom and the bride, that is, to God the Savior and the sacraments of the Church, it is said among other things: The daughters of Tyre will offer you gifts, the rich among the people will seek your favor (Ps. XLIV, 13). And the bridegroom himself speaks again to the Tyrian bride: Listen, daughter, and see, and incline your ear; and forget your people and your father's house, for the king desires your beauty. (Ibid. 11, 12). Hence, in the description of her beauty, it is said: The queen stands at your right hand, in a golden robe, adorned with various ornaments (Ibid., 10). And again: All the glory of the king's daughter is within (Ibid., 14). But if the king desires the beauty of penitent Tyre, and having the ornaments of various virtues, how much more will his reward and business be not in Tyre, where he does not dwell, but among those who live in the sight of the Lord! After they have repented, they will hear from the Lord and Savior: 'Eat, my friends, and drink, and be intoxicated, my beloved' (Song of Solomon 5:1). What it means to eat and drink, and be satisfied with the gathering of all virtues, the faithful reader understands. The temple was desolate for seventy years, as Jeremiah (Chapter 29), Daniel (Chapter 9), and Zechariah (Chapter 7) teach. And in Ezekiel (Chapter 16) we read about Sodom being restored to its former state, and about Egypt receiving its former abundance after the desolation and dryness of the land and the seven rivers. The number seventy signifies complete and perfect repentance, either in the span of seven days or in the completion of seven decades, so that just as Tyre, when the time of repentance is fulfilled, may return to its former state. Concerning this, I believe that the prostitute is referred to in the mystical language of Solomon's Proverbs: Do not look at the worst woman; for honey drips from the lips of the harlot, who fattens your throat for a short time, and afterwards you will find it bitter as gall (Prov. V, 2-4). For she peers through the window of her house onto the streets (Matth. VII): for the way that leads to death is wide and spacious, and she dares not tempt the wise, for she only lures the foolish, and she walks beside the corners, having lost the straight line: she talks to him in darkness and in gloom, and under the guise of pleasures she leads him like a victim to death. If she has been converted and has sung well, and has completed the time of perfect penance of years, she will eat and drink, and will be satisfied. Let Novatian hear, and let him be silent.
(Verse 16.) After seventy years, Tyre will be like the song of a prostitute. Take up the lyre, go around the city, forgotten prostitute, sing well, sing often, so that there will be a memory of you. Because you have prostituted yourself with many nations, and you have been left desolate, naked, and filthy with the filth of captivity, your former lovers have despised you. Now take up the lyre, sing songs of lamentation, go around the city, weep for your former brothel, and wash away the traces of your ancient error with tears, so that you may provoke the mercy of God in yourself.
[AD 420] Jerome on Isaiah 23:15-18