Deuteronomy 33:20

And of Gad he said
The tribe of Gad, as the Targums of Jonathan and Jerusalem:

blessed [be] he that enlargeth Gad;
that is, the Lord, to whom the praise and glory were to be given, who had appointed to Gad a large inheritance on the other side Jordan, and had settled him in it, and which became larger by the conquest of the Hagarites, and others, ( 1 Chronicles 5:18-22 ) ;

he dwelleth as a lion;
bold and courageous, secure, and without fear of any of his enemies, though near him, on his borders, as the Moabites and Ammonites were; of the same spirit and temper were the men of the tribe of Gad in the times of David, ( 1 Chronicles 12:8 ) ;

and teareth the arm with the crown of the head,
at once, just as a lion tears its prey; which figurative phrases are expressive of this tribe conquering and destroying strong and mighty men, signified by the "arm", in which the strength of a man lies, and of kings and governors, pointed at by the "crown of the head"; as the Targums of Onkelos and Jonathan; which was done in the times of Joshua, when with and under him they subdued and destroyed the kings and princes of the land of Canaan.