Aliya Summary: The tribes of Reuven and Gad owned lots of cattle. Seeing that the eastern bank of the Jordan — the lands of Sichon and Og which they had just conquered — had abundant pasture, they asked Moshe if they could remain and settle on the eastern bank. Moshe angrily responds that they are following in the footsteps of the spies who were fearful of the Canaanites, did not want to enter the land of Israel, and discouraged the entire nation from doing so. The Reuvenites and Gaddites respond that they will leave their cattle and families behind in fortified cities, and all their men will proceed into Israel with their brethren and lead them in the conquest of the land. Only after all the land has been conquered and settled would they return to the other side of the Jordan.
The actions of these tribes (that of fighting with their brethren) helped prove to Moshe and everyone that their intention wasn’t to disengage from the people, but merely a practical solution to having so much cattle. This proved appropriate and effective, and is an effective method of leading: with action, not words.