Jamieson, Fausset and Brown on Judges 1:16

16. the children of the Kenite, Moses' father-in-law, went up out of the city of palm trees with the children of Judah--called "the Kenite," as probably descended from the people of that name (Nu 24:21, 22). If he might not himself, his posterity did accept the invitation of Moses (Nu 10:32) to accompany the Israelites to Canaan. Their first encampment was in the "city of palm trees"--not Jericho, of course, which was utterly destroyed, but the surrounding district, perhaps En-gedi, in early times called Hazezon-tamar (Ge 14:7), from the palm-grove which sheltered it. Thence they removed for some unknown cause, and associating themselves with Judah, joined in an expedition against Arad, in the southern part of Canaan (Nu 21:1). On the conquest of that district, some of this pastoral people pitched their tents there, while others migrated to the north (Jud 4:17).