“Beginning from the north end.” That is, the north end of the Promised Land as it will be divided into tribal areas in the Millennial Kingdom.
“Dan, one portion.” The twelve tribes of Israel that were allotted a land area by Joshua (cp. Joshua 13-19) will receive a land area in the Millennial Kingdom. At the time of Joshua, the land was divided by lot. The High Priest would draw lots and the lot would determine how the Promised Land was to be allocated (Num. 26:55-56; 33:54; 34:13; 36:2; Josh. 14:2). However, it was believed that Yahweh determined how the lot fell. In the Millennial Kingdom the lot will not be used to determine the various tribal areas, but Yahweh will simply decree the areas of land the various tribes will get.
It seems fitting that in the Millennial Kingdom the tribe of Dan will get the northernmost section of land, furthest from Jerusalem and the temple. When Joshua divided up the Promised Land, Dan got a tribal area quite close to Jerusalem (Josh. 19:40-48). However, the Danites failed to conquer their land (Judg. 1:34-36), which they could have done with more focus, prayer, godly behavior, and possible help from other tribes. Then, instead of doing what it took to acquire the land that God had given them by lot, the majority of the tribe moved north and conquered the city of Laish and settled there, and immediately began worshiping idols (Judg. 18). Since the Danites chose to be the northernmost tribe throughout the Old Testament, it is fitting that God assigned them the northernmost tribal area in the Millennial Kingdom.
Nothing is said about the width from north to south of each tribal area except it seems that they are equal. Also, since the scholars are somewhat divided on the exact northern and southern boundaries of Israel, it is hard to exactly draw a map of the future Israel and put each tribe on that map. It does seem that Israel in the Millennial Kingdom will be somewhat larger than historic Israel, but by exactly how much is hard to determine. [For more on the future earth and Christ’s kingdom on earth, see Appendix 3, “Christ’s Future Kingdom on Earth”]