This Psalms focuses on praise for God. The first four verses give various ways to life his name and rejoice in his glory. These first verses are present tense, look at what God has blessed us with today.
In vs. 5 the author reflects on where God has brought us from and the people he has used: Abraham, Jacob and their descendants; he recalls the miracles, the pronouncements, the judgments.
In vs. 8, he reminds us that God's promises are forever. The Children of Israel wandered until God sent them into the land he promised them. They were wanderers without a home.
God called down destruction on the land and demanded the Israelites be honored and their prophets be respected.
About vs. 18 he begins to recount the story of Joseph and the calling of the Israelites out of Egypt.
God made the Children of Israel too fruitful to remain under the domination of Egypt and he enabled them to leave and go to the place he had prepared for them.
Vs. 11 promises them the Land of Canaan as their inheritance forever.
The author describes the actions of Moses and Aaron in winning the release of Israel from Egypt. He describes the plagues and devastation God brought on the land to give freedom to His chosen people. Some of the history becomes confused and fails to follow the chronology, but he never loses the presence of God in the direction and course the Israelites take.
The final verdict and effect was: the people God chose were given the land of Israel to celebrate God's victory, to keep his precepts and observe his laws. Hallalujah!