Joshua 19:9
7 Ain, Rimmon, Ether, and Ashan—a total of four cities and their towns, 8 as well as all the towns around these cities as far as Baalath Beer (Ramah of the Negev). This was the land assigned to the tribe of Simeon by its clans. 9 Simeon’s assigned land was taken from Judah’s allotted portion, for Judah’s territory was too large for them; so Simeon was assigned land within Judah. 10 The third lot belonged to the tribe of Zebulun by its clans. The border of their territory extended to Sarid. 11 Their border went up westward to Maralah and touched Dabbesheth and the valley near Jokneam.
Judges 1:3
1 After Joshua died, the Israelites asked the Lord, “Who should lead the invasion against the Canaanites and launch the attack?” 2 The Lord said, “The men of Judah should take the lead. Be sure of this! I am handing the land over to them.” 3 The men of Judah said to their relatives, the men of Simeon, “Invade our allotted land with us and help us attack the Canaanites. Then we will go with you into your allotted land.” So the men of Simeon went with them. 4 The men of Judah attacked, and the Lord handed the Canaanites and Perizzites over to them. They killed 10,000 men at Bezek. 5 They met Adoni-Bezek at Bezek and fought him. They defeated the Canaanites and Perizzites.
Notes and References
"... Judges 1:3 ... The fact that Judah unites with Simeon comes as no surprise after what is said about the territory of the tribe of Simeon in Joshua 19:9: “The inheritance of the children of Simeon was included in the share of the children of Judah, for the share of the children of Judah was too much for them. Therefore the children of Simeon had their inheritance within the inheritance of that people”. It shows that Judah was superior to Simeon and in this way also explains why Judah as the tribe descending from the fourth of the sons of Jacob takes the first place. The tribe of the oldest, Ruben, was not an option, because it had received its part outside the Promised Land (Joshua 13:8–23). The third, Levi, had not inherited land and had other cultic obligations (Joshua 13:33; 18:7). Simeon, the second of Jacob’s sons, did not have the status to become the leader of the Israelites. One could also see this as the fulfillment of the curse by Jacob on Simeon: “I will divide them in Jacob and scatter them in Israel” (Genesis 49:7). Simeon does not play an independent role. It is only mentioned once again, together with Judah, in Judges 1:17 ..."
Spronk, Klaas Historical Commentary on the Old Testament: Judges (pp. 53-54) Peeters, 2019