Numbers 26:29 - Matthew Poole's English Annotations on the Holy Bible

Gilead is here mentioned as Machir's only son, and therefore some conceive that the family of the Machirites, and of the Gileadites, are one and the same family, only called by two names; first Machirites, but afterwards Gileadites. Others make them distinct families, because Machir had other children, Genesis 1:23 1 Chronicles 7:14-16, which are called by their father's name, Machirites, whereas the children of his eldest son Gilead are called by his name, Gileadites. But though Machir had other children, it seems they and their posterity were extinct at this time, and that Machir alone was left and his posterity, as may be gathered by comparing this and the following verses with Joshua 17:1-3 1 Chronicles 7:14-19.