Numbers 26:54

Thou shalt give; thou, Moses, partly by thyself, for he divided the land beyond Jordan to the two tribes and a half; and partly by thy successor Joshua, whom thou shalt empower and command to do it. According to those that were numbered of him; according to the number of the families and persons now numbered, and being twenty years old, no regard being to be had either to any increase of the number by those who came up to that age between this time and the division of the land, or to the diminution of this number by the sword of Canaanites or otherwise.