Albert Barnes Commentary 2 Chronicles 19

Jehoshaphat ... returned to his house in peace - With the battle of Ramoth-gilead and the death of Ahab, the war came to an end. Because the combined attack of the two kings failed, their troops were withdrawn, and the enterprise they had undertaken was relinquished. The Syrians, satisfied with their victory, did not press the retreating enemy or carry the war into their enemies’ country.

Jehu ... went out to meet him - Compare 2 Chronicles 15:2. The monarch was therefore rebuked at the earliest possible moment and in the most effective way, as he was entering his capital at the head of his returning army. Jehu, 35 years previously, had worked in the northern kingdom and prophesied against Baasha (1 Kings 16:1–7), but had now come to Jerusalem as a prophet and historian (compare 2 Chronicles 20:34).

Shouldest thou help ... - As a matter of mere human policy, the conduct of Jehoshaphat in joining Ahab against the Syrians was not only justifiable but also wise and prudent. And the reasoning upon which such a policy was founded would have been unobjectionable but for one circumstance. Ahab was an idolater and had introduced into his kingdom a false religion of a new and most degraded type. This should have led Jehoshaphat to reject his alliance. Military success could only come from the blessing and protection of Yahweh, which such an alliance, if persisted in, was sure to forfeit.

Jehoshaphat, while declining to renounce the alliance with Israel (Compare to 2 Kings 3:7), was careful to show that he had no sympathy with idolatry and was determined to keep his people, so far as he possibly could, free from it. He therefore personally set about a second reformation, passing through the whole land from the extreme south to the extreme north (2 Chronicles 13:19).

It is impossible to determine the exact change Jehoshaphat made to the judicial system of Judah (Deuteronomy 16:18; 1 Chronicles 23:4). He probably found that corruption was widespread (2 Chronicles 19:7) and that the magistrates in some places were tainted by the prevailing idolatry.

Therefore, he made a new appointment of judges throughout the entire country, either by concentrating judicial authority in the hands of a few or by creating superior courts in the chief towns (“fenced cities”), with a right of appeal to these courts from the local village judges.

The “fathers of Israel” are the heads of families; the “chief of the fathers” are the great patriarchal chiefs, the admitted heads of great houses or clans. They were now admitted to share in the judicial office, which seems in David’s time to have been confined to the Levites (1 Chronicles 23:4).

For the judgment of the Lord, and for controversies — The first phrase refers to disputed cases concerning the performance of religious obligations. The term “controversies” includes all ordinary legal cases, whether criminal or civil.

When they returned to Jerusalem — This should instead be read as, and they returned to Jerusalem. This clause makes more sense if it is detached from the preceding words and connected to 2 Chronicles 19:9.