In the year that King Ahaz died. Here the fifteenth chapter ought to have begun, for the Prophet enters on a new subject; and this plainly shows how absurdly the chapters are divided, or rather torn asunder. Having spoken of the Babylonians, he passes to the Philistines; [1] or, perhaps, before speaking of the Babylonians, he addressed the Philistines, who, being the near neighbors of the Jews, cherished deadly hostility against them. They were the remainder of those nations whom the Israelites spared, though the Lord had commanded that they should be removed out of the midst of them. (Numbers 33:52; Deuteronomy 7:16.) Their unbelief in this matter was the reason why the Lord left these nations to be thorns, that they might prick their eyes; as the Scripture shows that the Lord had formerly threatened against them. (Numbers 33:55.) In consequence of the deadly animosities which existed between these two nations, whenever the Jews sustained any defeat, the Philistines reckoned it to be so much gain to themselves; for they wished the ruin of the Jews, and no occurrence could give them greater delight than when the Jews were reduced to the deepest adversity and distress. The Prophet therefore prophesies against them as against the constant enemies of the Church. It is proper to attend to the time when this vision was exhibited to the Prophet. So long as Ahaz lived, the Philistines were victorious. That wicked hypocrite, who had forsaken God, and eagerly sought the outward assistance of man, was punished for his treachery. During his reign the Philistines (2 Chronicles 28:18) recovered those towns which Uzziah (2 Chronicles 26:6, 7) had taken out of their hands; but after his death, they became still more courageous, for they expected that they would then gain all that they desired, because he who had been left as his heir was still a child; for Hezekiah, the new king, had neither shrewdness, nor authority, nor wisdom. These circumstances, therefore, ought to be carefully observed; for Isaiah has not the Philistines so much in his view, though he speaks to them, as the godly, whom he wishes to comfort and strengthen with good hope by this prophecy, who would otherwise have thought that the condition of Judea was entirely ruined, because they were attacked by enemies on all sides, and no assistance of any kind could be seen. To those persons, therefore, in their distressed and forlorn condition, Isaiah stretches out his hand, and bids them be of good courage, because the Lord would undoubtedly assist them. This burden. He calls this prophecy a burden, because it would be disagreeable and painful to the Philistines, who thought that they had got rid of every annoyance, because the Jews were hard pressed, and had no hope of bettering their condition; and therefore he threatens that the destruction of the Philistines also is at hand.

Footnotes

1 - The Hebrew word here used by Isaiah is phlst (Phelesheth,) from which was derived the word Philistia, afterwards changed to Palestina. An early genealogy informs us that the Philistim, or Philistines, were descendants of Mizraim, a son of Ham. (Genesis 10:14.) -- Ed

In the year that king Ahaz died - This is the caption or title to the following prophecy, which occupies the remainder of this chapter. This prophecy has no connection with the preceding; and should have been separated from it in the division into chapters. It relates solely to Philistia; and the design is to comfort the Jews with the assurance that they had nothing to apprehend from them. It is not to call the Philistines to lamentation and alarm, for there is no evidence that the prophecy was promulgated among them (Vitringa); but it is to assure the Jews that they would be in no danger from their invasion under the reign of the successor of Ahaz, and that God would more signally overthrow and subdue them than had been done in his time. It is not improbable that at the death of Ahaz, and with the prospect of a change in the government on the accession of his successor, the Philistines, the natural enemies of Judah, had meditated the invasion of the Jews. The Philistines had been subdued in the time of Azariah 2-Kings 15:1-7, or Uzziah, as he is called in 2-Chronicles 26:1, who was the son and successor of Amaziah. He broke down the wall of Gath, and the wall of Gabneh, and the wall of Ashdod, and effectually subdued and humbled them 2-Chronicles 26:6. In the time of Ahaz, and while he was engaged in his unhappy controversies with Syria and Ephraim, the Philistines took advantage of the enfeebled state of Judah, and made successful war on it, and took several of the towns 2-Chronicles 28:18; and at his death they had hope of being able to resist Judah, perhaps the more so as they apprehended that the reign of Hezekiah would be mild, peaceable, and unwarlike. Isaiah, in the prophecy before us, warns them not to entertain any such fallacious expectations, and assures them that his reign would be quite as disastrous to them as had been the reign of his predecessors.
Was this burden - See the note at Isaiah 13:1.

In the year that king Ahaz died was this burden - Uzziah had subdued the Philistines, 2-Chronicles 26:6, 2-Chronicles 26:7; but, taking advantage of the weak reign of Ahaz, they invaded Judea, and took, and held in possession, some cities in the southern part of the kingdom. On the death of Ahaz, Isaiah delivers this prophecy, threatening them with the destruction that Hezekiah, his son, and great-grandson of Uzziah, should bring upon them: which he effected; for "he smote the Philistines, even unto Gaza, and the borders thereof," 2-Kings 18:8. Uzziah, therefore, must be meant by the rod that smote them, and by the serpent from whom should spring the flying fiery serpent, Isaiah 14:29, that is, Hezekiah, a much more terrible enemy than even Uzziah had been.
The Targum renders the twenty-ninth verse in a singular way. "For, from the sons of Jesse shall come forth the Messiah; and his works among you shall be as the flying serpent."

In the year that king Ahaz died was this (q) burden.
(q) See Isaiah 13:1

In the year that King Ahaz died was this burden. The following heavy prophecy, concerning the destruction of the Philistines; whether it was delivered out before or after his death is not certain. Here some begin the "fifteenth" chapter Isaiah 15:1, and not improperly; henceforward prophecies are delivered out under another reign, as before under Uzziah, Jotham, and Ahaz, now under Hezekiah. This, according to Bishop Usher, was A. M. 3278 and before the Christian era 726.

Assurance is given of the destruction of the Philistines and their power, by famine and war. Hezekiah would be more terrible to them than Uzziah had been. Instead of rejoicing, there would be lamentation, for the whole land would be ruined. Such destruction will come upon the proud and rebellious, but the Lord founded Zion for a refuge to poor sinners, who flee from the wrath to come, and trust in his mercy through Christ Jesus. Let us tell all around of our comforts and security, and exhort them to seek the same refuge and salvation.

PROPHECY AGAINST PHILISTIA. (Isaiah 14:28-32)
In . . . year . . . Ahaz died--726 B.C. Probably it was in this year that the Philistines threw off the yoke put on them by Uzziah.

This is one of the prophecies the date of which is fixed in Isaiah 14:28. "In the year of the death of king Ahaz the following oracle was uttered." "The year of the death of king Aha"Z was (as in Isaiah 6:1) the year in which the death of Ahaz was to take place. In that year the Philistines still remained in those possessions, their hold of which was so shameful to Judah, and had not yet met with any humiliating retribution. But this year was the turning-point; for Hezekiah, the successor of Ahaz, not only recovered the cities that they had taken, but thoroughly defeated them in their own land (2-Kings 18:8).

This burden - This following burdensome prophecy concerning the Philistines, who in Ahaz's time, made an inroad into Judah, and took divers of their cities.