2 Sam 22:30 is a particularly vivid image: “For by you I can run against a troop, and by my God I can leap over a wall.” This verse might be the Hebrew Bible’s version of “I can do all things through Christ,” since David expresses the idea that the for the one who is rescued and vindicated by God and walking in the light which God provides (verse 29), he can do remarkable things indeed!
To “run against a troop” means that in the strength of the Lord David is able to stand up to an entire army himself. This is not far from his own experience with Goliath, and in 2 Sam 23:8-39 there are several stories of David’s soldiers who did in fact stand up to a large enemy force by themselves, super-human feats which can only be credited to the power of God. In 23:11, for example, Shammah defends a field against the Philistines single-handed. In 23:18, Abishai slays 300 Philistines with his spear.
Likewise, to “leap over a wall” is a feat of incredible strength which goes beyond a human’s ability.
This is not a fence or wall between two properties, this is a major city wall, perhaps 20 feet tall and heavily guarded. David entered Jerusalem through the water system, narrow and dark caves. But in the Lord he is able to hurdle the defenses of the enemy as if they are nothing at all. This photograph shows the reconstructed walls of Arad, a citadel in a hill in the southern part of Judah’s territory. I show it as an example of the kind of wall David is referring to in this Psalm. He is not leaping a short fence or jumping something which is humanly possible. To leap over the wall of the enemy’s city is impossible physically — only by the power of God can David do “all things.”
There are other military metaphors in this section which describe David as an excellent warrior because the Lord rescued him. For example, he runs like a deer (34), he breaks bows of bronze (35), he “consumed” his enemies (39), he grinds his enemies to dust (43). All of these images ought to be take together to show that David is the ultimate victor. He was a man drowning in the chaotic waters of the Sea, about to be dragged down to Sheol itself, yet the Lord rescued him, put him in a safe place, and made him to be his king forever (50-51).
David’s whole life is an example of this transformation from a young boy to warrior, from enemy of the state to King of Israel. Looking back over the years, undoubtedly David saw his life as proof that the Lord was at work – David himself could not take credit for anything he did!