Went out too little for them - This is certainly the meaning of the passage; but our translators have been obliged to add the words too little to make this sense apparent. Houbigant contends that an ancient copyist, meeting frequently with the words ויצאהגבול vaiyetse haggebul, in the preceding history, became so familiarized to them that he wrote them here instead of הגבול ויאץ vaiyaats haggebul, and the border of the children of Dan was Strait for them. It was on this account that they were obliged to go and fight against Leshem, and take and possess it, their former inheritance being too strait for their increasing population.
And called Leshem, Dan - This city was situated near the origin of Jordan, at the utmost northern extremity of the promised land, as Beer-sheba was at that of the south; and as after its capture by the Danites it was called Dan, hence arose the expression from Dan even to Beer-sheba, which always signified the whole extent of the promised land. Some suppose that Leshem was the same with Caesarea Philippi, but others with reason reject this opinion. It must be granted that the whole account given in this verse refers indisputably to a fact which did not take place till after the death of Joshua. It is another of the marginal or explicative notes which were added by some later hand. The whole account of this expedition of the Danites against Leshem is circumstantially given in the book of Judges, chapter 18, and to that chapter the reader is referred.
The words “too little” are an insertion of the King James Version Render rather, “the border of the children of Dan was extended.” The Hebrew appears to mean “the children of Dan enlarged their border because they had not room enough.”
The reason of this was that the Danites, a numerous tribe (Numbers 26:5 note), found themselves Judges 1:34-35 cooped up among the hills by the powerful and warlike Amorites. Hence, the Danite expedition (see the marginal reference), which surprised the Sidonion inhabitants of Leshem, an unwarlike and peaceable race, exterminated them, and annexed their city and territory to the portion of Dan.