Sforno on Deuteronomy 33:20/ספורנו על דברים ל״ג:כ׳

1ברוך מרחיב גד, Who has given him a larger tract of land on the east bank of the Jordan than any other tribe received even in that part of the country. For while it is true that the lands of Sichon and Og were larger in the number of square meters accorded to the tribes on the west bank, the latter were of the category known as “flowing with milk and honey,” whereas the land on the east bank was primarily grazing land as opposed to “homesteading” land, i.e. farming land.

2כלביא שכן, he deserves the extra acreage as he holds his own against enemies that surround him and he behaves like a brave courageous lion though badly outnumbered. Such a lion does not hesitate to devour what is around him.