until Yahweh have given your brothers rest, as [he has given] you, and they also have possessed the land which Yahweh your God gives them: then you shall return to the land of your possession, and possess it, which Moses the servant of Yahweh gave you beyond the Jordan toward the sunrise.
Not all the warriors from the two and one-half tribes went with (not "before," Joshua 1:14) their brethren across the Jordan. Only 40,000 of the 110,000 did (cf. Joshua 4:13 and Numbers 26:7; Numbers 26:18; Numbers 26:34). The remainder evidently stayed in Transjordan. We should understand "all" (Joshua 1:14) in this limited sense.