The two key words in Psalm 89 are "covenant" and "faithfulness" or "kindness". These pertain to God. Their counterparts on the side of Israel are "forsake", "violate" and associated negative terms. Israel suffered so much during its history that it must have been sometimes tempting for some of them to imagine that God was unfaithful to the Covenant and was incapable or unwilling to fulfil all the divine promises.

The Covenant was purely a gift of God to Israel and not an agreement reached between God and Israel as if between two equal negotiating partners. Nevertheless there were two sides to the Covenant in that there were conditions that David's descendants had to keep: "if his sons forsake my law... if they violate my statutes..." Failure to keep God's law had serious consequences bringing severe punishment upon the people. The Psalmist takes great care to assure Israel that God was not unfaithful to his promises: a Son of David would reign forever. Beyond the succeeding generations of David's descendants and their frequent infidelity, God was preparing the coming of the Messiah: Jesus is the fulfilment of all God's promises.