Tribes to Settle East of the Jordan 

The tribes of Reuben and Gad had a lot of cattle. The land of the Amorites had just been conquered (Numbers 21). And, with much good pastureland for grazing, these tribes decided that it would be a good place to settle down and make a home. So they let their desire for settlement be known to Moses. But Moses, all too familiar with Israel's past rebellions, was angered—and rightfully so. After all, there were still battles to be fought in the Promised Land, across the Jordan. Moses was concerned that their actions would discourage the other tribes if they bailed out now. And refusal to enter the Promised Land was the very sin for which God had punished Israel with its decades of wandering. Moses brings up the past, in effect asking, "Do you want to go through 40 more years in the wilderness?... Your fathers who spied out the Promised Land came back and discouraged everyone, causing about three million people to die in the wilderness. Do you want to do the same thing?" (compare verses 8, 13). "You are doing the same thing your fathers did, and you too will bring the wrath of God on us," Moses basically told them (compare verse 14).

The Reubenites and Gadites reassured Moses that they would fight alongside the other tribes to subdue the land of Canaan. But they requested that they be allowed to construct settlements for their children and cattle on the east side of the Jordan River, explaining that the men of fighting age would then leave them there while they went to help secure the land across the Jordan for all the rest of Israel. They would only return when the Israelite conquest of Canaan was complete and everyone had received his inheritance (verses 18-22). Moses agreed that this would be acceptable as long as they didn't back out of the agreement (verse 23). He wasn't going with them, so he had to pass the decision on to Eleazar and Joshua, who would lead Israel across the Jordan (verse 28).

It isn't until the end of the chapter that we learn that half of the tribe of Manasseh would also have its inheritance east of the Jordan. Yet there were still some Amorites whom the Manassites had to dispossess at this point (verse 39). In the end, as we will later see, about 40,000 men of war from the two and a half eastern tribes do accompany Joshua into the Promised Land (Joshua 4:12-13).