Judges 1:30

Neither did Zebulun. The author now begins to relate the experiences of the tribes whose portions were situated in northern Palestine beyond the plain of Esdraelon. Nothing is said of the tribe of Issachar, although in the song of Deborah (ch. 5) it is represented as one of the more aggressive tribes. The story with respect to each of these tribes as given here is about the same. They were not strong enough to attack the fortresses in their allotted territories. Even in the mountains they were unable to gain the mastery as the tribes farther to the south had done. They merely whittled out little sections here and there wherever they could, and thus wedged themselves in among the older settlements.