Judah Could Not Drive Out Inhabitants

Judges 1:19-21
 
19  And the LORD was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron. 
20  And they gave Hebron unto Caleb, as Moses said: and he expelled thence the three sons of Anak. 
21  And the children of Benjamin did not drive out the Jebusites that inhabited Jerusalem; but the Jebusites dwell with the children of Benjamin in Jerusalem unto this day.