2 Chronicles 35:20

20. After all this, when Josiah had prepared the temple--He most probably calculated that the restoration of the divine worship, with the revival of vital religion in the land, would lead, according to God's promise and the uniform experience of the Hebrew people, to a period of settled peace and increased prosperity. His hopes were disappointed. The bright interval of tranquillity that followed his re-establishment of the true religion was brief. But it must be observed that this interruption did not proceed from any unfaithfulness in the divine promise, but from the state into which the kingdom of Judah had brought itself by the national apostasy, which was drawing down upon it the long threatened but long deferred judgments of God. Necho king of Egypt came up to fight against Carchemish by Euphrates--Necho, son of Psammetichus, succeeded to the throne of Egypt in the twentieth year of Josiah. He was a bold and enterprising king, who entered with all his heart into the struggle which the two great powers of Egypt and Assyria had long carried on for the political ascendency. Each, jealous of the aggressive movements of its rival, was desirous to maintain Palestine as a frontier barrier. After the overthrow of Israel, the kingdom of Judah became in that respect doubly important. Although the king and people had a strong bias for alliance with Egypt, yet from the time of Manasseh it had become a vassal of Assyria. Josiah, true to his political no less than his religious engagements, thought himself bound to support the interests of his Assyrian liege lord. Hence, when "Necho king of Egypt came up to fight Carchemish, Josiah went out against him." Carchemish, on the eastern side of the Euphrates, was the key of Assyria on the west, and in going thither the king of Egypt would transport his troops by sea along the coast of Palestine, northwards. Josiah, as a faithful vassal, resolved to oppose Necho's march across the northern parts of that country. They met in the "valley of Megiddo," that is, the valley or plain of Esdraelon. The Egyptian king had come either by water or through the plains of Philistia, keeping constantly along the coast, round the northwest corner of Carmel, and so to the great plain of Megiddo. This was not only his direct way to the Euphrates, but the only route fit for his chariots, while thereby also he left Judah and Jerusalem quite to his right. In this valley, however, the Egyptian army had necessarily to strike across the country, and it was on that occasion that Josiah could most conveniently intercept his passage. To avoid the difficulty of passing the river Kishon, Necho kept to the south of it, and must, therefore, have come past Megiddo. Josiah, in following with his chariots and horsemen from Jerusalem, had to march northwards along the highway through Samaria by Kefr-Kud (the ancient Caper-Cotia) to Megiddo [Van De Velde].

Robert Jamieson, A. R. Fausset & David Brown, 1871 · public domain

Verse 20 Necho king of Egypt - Pharaoh the lame, says the Targum.

Adam Clarke, 1831 · public domain

The Scripture does not condemn Josiah's conduct in opposing Pharaoh. Yet Josiah seems to deserve blame for not inquiring of the Lord after he was warned; his death might be a rebuke for his rashness, but it was a judgment on a hypocritical and wicked people. He that lives a life of repentance, faith, and obedience, cannot be affected by the sudden manner in which he is removed. The people lamented him. Many mourn over sufferings, who will not forsake the sins that caused God to send them. Yet this alone can turn away judgments. If we blame Josiah's conduct, we should be watchful, lest we be cut down in a way dishonourable to our profession.

Matthew Henry, 1706 · public domain