Psalm 89, known as Psalm 88 in the Septuagint and Vulgate numbering, is a profound royal psalm that extols God's unwavering mercies and His covenant with David. Attributed in its superscription to Ethan the Ezrahite, a renowned wise man and possibly a Levite musician during the reigns of David and Solomon, the psalm likely originated in the period of the united monarchy around the 10th century BC. Ethan, mentioned in 1 Kings 4:31 for his wisdom surpassed only by Solomon, may have been the same as Jeduthun, a temple musician appointed by David. Scholars suggest it was composed amid a crisis threatening the Davidic line, such as during the Babylonian exile or earlier upheavals, voicing lament over the apparent failure of God's promises while reaffirming faith in divine fidelity. The psalm blends praise, covenant recollection, and plea, drawing on ancient Near Eastern poetic styles akin to Ugaritic literature.

The selected verses (2-3, 4-5, 27, 29, with refrain from 37a) proclaim God's eternal mercies, established like the heavens, and His oath to David: an everlasting dynasty and throne. David is depicted calling God "my father, my God, the rock of my salvation," with assurances of enduring faithful love and a lasting covenant. The refrain, "His descendants shall continue for ever," emphasises the perpetual nature of this promise.

In the liturgy, these verses serve as the responsorial psalm for the Solemnity of Saint Joseph, Spouse of the Blessed Virgin Mary, celebrated on 19 March. This choice holds deep significance, linking the Davidic covenant to Joseph's role. As a descendant of David (Matthew 1:1-16), Joseph is the legal father of Jesus, the Messiah who fulfils the eternal kingship promised to David's line. The psalm underscores Joseph's place in salvation history: as husband to Mary and guardian of the Christ child, he embodies faithful stewardship amid God's plan. It portrays God as a protective father, mirroring Joseph's paternal care, and highlights themes of fidelity and endurance. Thus, the psalm invites reflection on Joseph's quiet obedience, transforming Old Testament prophecy into New Testament reality, affirming that through Jesus, David's descendants indeed endure forever.