This Psalm is a homily, in a set of observations that may not necessarily be related. The overarching theme is not to become concerned at the propperity of the wicked and that YHWH will fulfill His promises of prosperity to the faithful (Deut. 28). 
The is a a part of the “Deuteronomistic Theology” of the early Israelites. God promised them the inheritance of the Promised Land for obedience. It was a part of the covenant pact made with Abraham (Gen. 12). Remember that God chose one peoples’ history to begin showing His interaction with all of humanity. Some of the promises made to the Israelites were specific to them for their time. For Christians today, this is a reminder of God’s faithfulness to those who are obedient.
 John Goldingay, Psalms: 1-41 in Baker Comentary on the Old Testament: Wisdom and Psalms, vol. 1, ed. Tremper Longman III (Grand Rapids: Baker Academic, 2006) 517-520.