Matthew Poole and continuators on Judges 1:2

2 And the LORD said, Judah shall go up: behold, I have delivered the land into his hand.

Not a person so called, but the Tribe of Iudah, as is manifest from v. 3, 4, 8, 9. which is chosen for the first enterprise, because they were both most populous, and so most needing enlargement; and withal most Valiant, and therefore most likely to succeed: for God chuseth fit means for the work which he designs; and because the Canaanites were numerous and strong in those parts, and therefore were in time to be suppressed, before they grew too strong for them.