Blessed be he that enlargeth Gad - As deliverance out of distress is termed enlarging, (see Psalm 4:1;), this may refer to God's deliverance of the tribe of Gad out of that distress mentioned Genesis 49:19, and to the enlargement obtained through means of Jephthah, Judges 11:33, and probably also to the victories obtained by Gad and Reuben over the Hagarites, 1 Chronicles 5:18-20.
He dwelleth as a lion - Probably the epithet of lion or lion-like was applied to this tribe from their fierce and warlike disposition. And on this supposition, 1 Chronicles 12:8, will appear to be a sufficient comment: And of the Gadites there were men of might, men of war for the battle, that could handle shield and buckler, whose faces were Like The Faces Of Lions, and were as swift as the roes upon the mountains. Tearing the arm or shoulder with the crown of the head seems simply to mean that no force should be able to prevail over them, or stand against them; as the arm or shoulder signifies dominion, and the crown of the head, sovereign princes.
i. e., Blessed be God who shall grant to Gad a spacious territory. Compare the blessing of Shem Genesis 9:26.
With the crown - Rather, yea, the crown. The warlike character of this tribe is shown by their leading the van in the long campaigns of Joshua (compare Joshua 4:12-13; Joshua 22:1-4). Compare also 1 Chronicles 5:18-22; 1 Chronicles 12:8 ff, and the acts of Jehu, the Gadite, in 2 Kings 9; 10.