שופטים, פרק א׳, פסוק כ׳

The consolidation of power in the mountainous region reached its final stage when the city of Hebron was handed over to Caleb. This transfer of land completed the broader picture of the tribe of Judah's control over the hill country [ביאור שטיינזלץ].

Securing the city required a united effort. The members of the tribe had to actively assist Caleb in the conquest to ensure that an old promise, originally made to him by Moses, was fully honored. Even though the tribe fought alongside him, their military goals were highly specific. They focused their efforts entirely on capturing Hebron itself and deliberately avoided conquering any of the surrounding territories [מלבי״ם]. Following the successful capture of the city, Caleb took control and drove out the sons of Anak, a local population known for being exceptionally tall [מצודת ציון].