Sidon at the end of the second millennium BC was a powerful Phoenician city; indeed, the term Sidonians
stands for the Phoenicians.
1 The phrase after the manner of the Sidonians
is difficult to translate. The current translation suggests that the Laishites had adopted the Sidonian customs or general way of life. The Sidonians were a seafaring people known more for their maritime trading interests than for military activity or political control.2 The phrase could alternately be rendered, according to the rule of the Sidonians.
This would suggest that the Laishites had some sort of treaty with the Sidonians, whereby they lived under their umbrella.3 In context, the former option (which the ESV adopts) seems more likely (although it does not have to rule out the second option as possible).
7 Then the five men departed and came to Laish and saw the people who were there, how they lived in security, after the manner of the Sidonians, quiet and unsuspecting, lacking nothing that is in the earth and possessing wealth, and how they were far from the Sidonians and had no dealings with anyone.