“from Kadesh-barnea even as far as Gaza.” This is the southernmost reaches of Israel’s conquest in Joshua 10. The southern border of Judah was south of Kadesh-barnea, which is in the deep south of the Negev, and is where Moses and Israel were camped when Moses sent the spies to spy out the Promised Land (Num. 13:1-25; 32:8). Gaza is about 60 miles almost due north of Kadesh-barnea, but is on the Mediterranean Coast of Judah. Kadesh-barnea to Gaza defined the southern extent of Joshua’s conquest. However, Joshua is never said to have conquered Gaza; it is not listed in the cities he conquered in Joshua 12:9-34. It is likely that his army chased men as far as Gaza.
“Goshen.” This is not the Goshen in Egypt, but most likely the Goshen of Joshua 15:51, a town in the hill country of Judah. It is possible that it is a site in northern Judah/Benjamin from which a line could be drawn similar to the line drawn “from Kadesh-barnea even as far as Gaza.” In that case, Joshua 10:41 would be drawing two lines delineating the southern and northern borders of the conquest described in Joshua 10. Another suggestion that has been made by scholars is that the “land of Goshen” is the southern slopes toward the Negev south of Hebron, near Debir. A ruin called Khirbet Tatrit has been suggested. If so, “Goshen to Gibeon” would delineate “the Hill Country (of Judah)”
“Goshen even as far as Gibeon.” Gibeon was where this battle for the southern part of Israel started (Josh. 10:10).