Three Judges of Israel
All of the Israelites’ weeping and sacrifice did nothing to restrain them from mixing with the detestable heathen in the Land of Promise. “And they took their daughters to be their wives, and gave their daughters to their sons; and they served their gods” (verse 6). Israel simply did not have a heart to obey God (Deuteronomy 5:29 Deuteronomy 5:29O that there were such an heart in them, that they would fear me, and keep all my commandments always, that it might be well with them, and with their children for ever!
American King James Version×). The effect was disastrous: conquest and reduction to servitude under gentile kings. The first servitude in the land was under Cushan-Rishathaim, king of Mesopotamia, and it lasted for eight years. This king’s name “means ‘Cushan of Double Wickedness’; this may not have been his actual name, but instead a name pinned on him by the author of Judges for ridicule [or perhaps one that the people called him for the same reason]. Note that this name is found four times in two verses (vv. 8, 10), which may support the point that the author was mocking the king” (Nelson Study Bible, note on Judges 3:8 Judges 3:8Therefore the anger of the LORD was hot against Israel, and he sold them into the hand of Chushanrishathaim king of Mesopotamia: and the children of Israel served Chushanrishathaim eight years.
American King James Version×). The brevity of the servitude under him may be accounted for by the fact that it was Othniel, the nephew and son-in-law of Caleb (Judges 3:9 Judges 3:9And when the children of Israel cried to the LORD, the LORD raised up a deliverer to the children of Israel, who delivered them, even Othniel the son of Kenaz, Caleb’s younger brother.
American King James Version×; compare Joshua 15:16-17 Joshua 15:16-17  And Caleb said, He that smites Kirjathsepher, and takes it, to him will I give Achsah my daughter to wife.  And Othniel the son of Kenaz, the brother of Caleb, took it: and he gave him Achsah his daughter to wife.
American King James Version×), whom God used to restore Israel’s freedom. Othniel probably saw and participated in the initial conquest, making him a transitional figure from the generation that saw the earlier works (compare Judges 2:7 Judges 2:7And the people served the LORD all the days of Joshua, and all the days of the elders that outlived Joshua, who had seen all the great works of the LORD, that he did for Israel.
American King James Version×) to those who didn’t. It may be that some of the first-generation zeal was in Othniel and that his fearless leadership was able to rally a more repentant and zealous spirit in his brethren. For 40 years Israel had freedom. But after the death of Othniel and his restraining influence, Israel returned to the slavery of idolatry.
With the return to idolatry came the inevitable return of servitude to a foreign nation. This time it was Eglon, king of Moab, who subdued Israel. After 18 years, God provided release through Ehud, who assassinated Eglon. Once again, Israel had rest, this time for 80 years. But once again, Israel lapsed into disobedience.
The deliverance by Shamgar is related in a single line. It may be that he judged contemporaneously with Ehud, perhaps taking a more westerly area of administration. He is said to have slain a large number of Philistines, which would put his activity in the western lowlands of Judah. We cannot know for certain. Since Israel is said to have gone astray after Ehud died (Judges 4:1 Judges 4:1And the children of Israel again did evil in the sight of the LORD, when Ehud was dead.
American King James Version×) we may conclude that Shamgar’s deliverance occurred after Ehud’s judgeship began (Judges 3:31 Judges 3:31And after him was Shamgar the son of Anath, which slew of the Philistines six hundred men with an ox goad: and he also delivered Israel.
American King James Version×) and that he died before Ehud. Beyond that, The Nelson Study Bible makes some interesting points: “Moreover, Shamgar delivered Israel but did not judge it [at least, that is not expressly stated]. Even the name Shamgar is not Hebrew. Yet he was the son of Anath—clearly a Semitic name. This may mean that he was from the town of Beth-Anath in Galilee; more probably, however, Anath is derived from the name of the Canaanite warrior goddess. If so, then it is ironic that God used a foreign warrior to deliver Israel” (note on 3:31).