What does Judges 18:15 mean?

The five scouts from Dan somehow identified the Levite priest who served in Micah's household (Judges 17:1–5) even before their first visit there (Judges 18:3). During that visit, they asked him many questions about how he came to live there. They also asked him to ask the Lord if their mission would be successful. They took his response as a positive sign they should keep going (Judges 18:4–6).

Now they have returned to Micah's home. Given Micah's family wealth, this was probably a homestead with multiple buildings. This time, however, the men from Dan come as part of a six-hundred-man army (Judges 18:11–13) on its way to slaughter the residents of a northern town (Judges 18:7–10). The Danites enter the house of the young Levite priest and treat him with apparent respect, asking about his welfare, as if they are old friends.