Kadesh-barnea lay in the south of Canaan, Numbers 34:4 Deuteronomy 1:19 Joshua 15:3. Gaza was in the south-west of Canaan. So he here signifies that Joshua did in this expedition subdue all those parts which lay south and west from Gilgal. Goshen; not that Goshen in Egypt, but another in Judah, Joshua 11:16, Joshua 15:51.
Related Commentaries of Joshua 10:41
Joshua 10:41
41 And Joshua smote them from Kadeshbarnea even unto Gaza, and all the country of Goshen, even unto Gibeon.