Joshua 24:31
And Israel served the LORD all the days of Joshua, and all the days of the elders that overlived Joshua, and which had known all the works of the LORD, that he had done for Israel. And Israel served the LORD all the days of Joshua, and all the days of the elders that overlived Joshua, and which had known all the works of the LORD, that he had done for Israel.
The verse belongs to the time after the wars of conquest, when the Lord had given Israel rest from its enemies. At that time Joshua was living in retirement at Timnath-serah. It records that Israel served the Lord faithfully throughout Joshua's lifetime and throughout the lifetimes of the elders who outlived him. Those elders had personally known and witnessed all the works the Lord had done for Israel.
Israel's continuing loyalty through those years is the clearest testimony to Joshua's character and work as its leader.