This Psalm celebrates the intervention of God. Jehovah-Adonai, on behalf of His earthly people, “God shall arise, his enemies shall be scattered, and they that hate him shall flee before him.” Moses could ask God to do this when the ark of the Lord was lifted up for each journey in the wilderness. The psalmist here uses similar language, with this difference: Moses asks God to arise that the desired result may be obtained; the psalmist awaits in confidence its accomplishment, describing in the two following verses what the issue will be to the wicked and to the righteous. After this to verse 9 we have God's character set forth, as manifested in His actions, for which He is to be praised, and His majesty as displayed when marching before His people through the wilderness.
But the remembrance of His ways of old strengthens the hope in the hearts of His faithful people of yet further displays of power and goodness on behalf of the nation. The prophetic description of this forms the chief subject of the psalm, grounded on what is stated in verse 18, the ascension of Adonai leading captive captivity, and receiving gifts in the man, that Jehovah-God might dwell among them, The Church now enjoys gifts secured by His ascension. Israel also has gifts secured to her, but not yet to be enjoyed; so the psalmist from verse 9 to 24 speaks almost always in the future. This the Authorized Version in part fails to point out. So, I submit, we should read: “Thou, O God, wilt send a plentiful rain on thine inheritance.” On what is this hope based? His past dealings with them. “When weary, thou Last refreshed it;” moreover, it has been in former times the dwelling-place of His congregation. “Thy congregation hath dwelt therein.” Hence they draw the conclusion, and rightly, “Thou, O God, wilt prepare of thy goodness for the afflicted. Adonai will give a word, the armies who publish it shall be a great host. Kings with their armies shall flee, shall flee; she that tarrieth at home shall divide the spoil. If ye shall lie among the pots, yet shall ye be as the wings of a dove covered with silver, and her feathers with yellow gold. When the Almighty scatters kings in her, she shall be as white as snow in Salmon.” Again, “God has desired to dwell in.” (Ver. 16.)
I would add that we have in this psalm nearly all the different names of God: El, Elohim (God); Shaddai (Almighty); Jehovah, Adonai, Jah (Lord). Elohim is the name of God in creation (Gen. 1); Shaddai and Jehovah, the names under which God revealed Himself respectively to Abraham and Israel. Adonai, as here described, is the One who has ascended up on high; but if ascended, He descended first into the lower parts of the earth. Yet He is Jehovah. (Ver. 20.) “To Jehovah Adonai belong the goings out to death.” Jab is first met with in Ex. 15:2, after the deliverance of the people from Pharaoh at the Red Sea. Often met with in the Psalms in the well-known compound, Hallelu-jah; it occurs also in Ex. 17:16; twice in this Psa. 4; 18 also in Psa. 77:11; 89:8; 94:7, 12; 102:18; 115:17, 18; 118:5, 14, 17, 18, 19; 122:4; 130:3; 135:4; 150:6; and in Isa. 12:2; 26:4; 38:11. If we examine the context of most of the places where it occurs, I think we shall be persuaded it is not a mere abbreviation of Jehovah, but has a significance of its own, reminding His people that He has, and will, interpose in power on their behalf. So Jehovah characterizes God as the one true and self-existing Being (in opposition to the false gods of the heathen) who has made a covenant with Israel. Jah characterizes Him specially as the Deliverer of His people from Egypt in time past, who will deliver them from all their enemies again.