And David became greater and greater, for the LORD God of Hosts was with him.
If Salem, the place of which Melchizedec was king, was Jerusalem (as seems probable from Psa 76:2), it was famous in Abraham's time. Joshua, in his time, found it the chief city of the south part of Canaan, Jos 10:1-3. It fell to Benjamin's lot (Jos 18:28), but joined close to Judah's, Jos 15:8.
Commenting on 2 Samuel 5:6-10
And David went on, and grew great,.... In honour and wealth, in fame and reputation, in subduing his enemies, obtaining conquests over them, and enlarging his dominions: and the Lord God of hosts, of armies above and below: was with him: to whom all his prosperity and success was owing. The Targum is,"the Word of the Lord God of hosts was for his help,''or his helper.
2Sa 5:10 And David increased in greatness, i.e., in power and fame, for Jehovah the God of hosts was with him.