What does Judges 18:30 mean?

Dan, a tribe of Israel meant to live in a central area of the Promised Land (Joshua 19:40–46), failed to conquer their territory (Judges 1:34–36). Feeling cramped, they sought new land (Judges 18:1–2), found an unsuspecting town of peaceful inhabitants (Judges 18:7), and butchered all of them (Judges 18:27–28). This town was formerly known as Laish, in the far north of Israel. The conquerors have changed the name of the town to Dan. What was described in the prior verses gives more detail to the summary presented in the book of Joshua (Joshua 19:47–48).

After brutally taking territory meant for another tribe (Joshua 17), they create their own system of religion. This is entirely opposed to the Lord's own commands about how His people Israel must worship Him. The Danites had stolen an ample collection of religious icons (Judges 18:14–19), including idols of false gods. Even the few items of that haul connected to Yahweh were unspiritual and immoral: the use of any carved image for worshiping God was forbidden (Exodus 20:3–5).

Now we learn more about the young Levite man (Judges 17:7–13) who had been hired as a private priest. He gladly came along with the robbers from Dan. He was overjoyed to become priest to their entire tribe and helped them plunder his former employer (Judges 18:20). The writer of Judges identifies the Levite as Jonathan, son of Gershom. This makes this idolatrous priest a grandson of Moses himself (Exodus 2:22). Modern commentators agree there is no reason not to believe this is the case. Moses and Zipporah did have a son named Gershom (Exodus 2:22). It is devastating to see Moses' own grandson so thoroughly violating the commands of God's law. Yet this fits with the statement made at the beginning of this book that the generation after Joshua's death did not know the Lord or the work He had done for Israel (Judges 2:10).

This also helps to place the events of chapters 17 and 18 in a historical framework. If Jonathan, the false priest of Dan, is the grandson of Moses, these events happened long before Samson's life, as depicted in chapters 13—16. The last chapters of the book of Judges are meant to further explain how far Israel had fallen into depravity (Judges 17:6; 18:1; 19:1; 21:25). The stories of the individual judges (Judges 2:16–19) have already been told.

Jonathan and his sons establish a center of false worship, serving as "priests" in Dan. This violates the commands of Deuteronomy 12:5–6 about where God must be worshiped: "But you shall seek the place that the Lord your God will choose out of all your tribes to put his name and make his habitation there. There you shall go, and there you shall bring your burnt offerings and your sacrifices, your tithes and the contribution that you present, your vow offerings, your freewill offerings, and the firstborn of your herd and of your flock."

The place God had chosen for worship of Himself in Israel was not Dan. At this stage in Israel's history, it was Shiloh, in the territory of Ephraim in central Israel (Judges 18:31). The false worship in Dan continued until "the day of the captivity of the land." Some scholars understand this to be a reference to the Assyrian deportation of Israelite people in 734 BC.