Ethan announced two major themes of this psalm in verses 1 and 2. These are the loyal love (Heb. hesed) and faithfulness of Yahweh. References to God's loyal love occur in verses 1, 2, 14, 24, 28, 33, and 49. He referred to God's faithfulness in verses 1, 2, 5, 8, 24, 33, and 49. He proceeded to appeal to God to honor His promises to David on the basis of these qualities.
The psalmist restated the Davidic Covenant promises in verses 3 and 4. Interestingly the word "covenant"does not occur in either 2 Samuel 7 or 1 Chronicles 17, the two places in the Old Testament where God recorded the giving of that covenant. Three key terms used in these two verses also recur throughout this psalm. These are "covenant"(vv. 3, 28, 34, and 39), "David My servant"(vv. 3, 20, and 50 where it is just "My servant"), and "throne"(vv. 4, 14, 29, 36, and 44). Obviously the Davidic Covenant was central in the writer's thinking in this psalm.
"The background for the Davidic Covenant and the sonship imagery associated with it is the ancient Near Eastern covenant of grant, whereby a king would reward a faithful servant by elevating him to the position of sonship' and granting him special gifts, usually related to land and dynasty. Unlike the conditional suzerain-vassal treaty, after which the Mosaic Covenant was patterned, the covenant of grant was an unconditional, promissory grant which could not be taken away from the recipient.154Consequently God's covenantal promises to David were guaranteed by an irrevocable divine oath (89:3, 28-37; 132:11)."155