Psalm 18 (17 in the Septuagint and Vulgate numbering) is a royal song of thanksgiving, one of the longest psalms in the Psalter. Its superscription presents it as a song of David, the servant of the Lord, sung on the day the Lord delivered him from all his enemies and from the hand of Saul. A nearly identical version stands in 2 Samuel 22, near the close of David’s story. Many scholars therefore regard the psalm as ancient, rooted in David’s life in the 10th century BC, even if it later received liturgical shaping for Temple worship. It is a hymn of personal deliverance that also speaks for the Davidic king: God is rock, fortress, shield and saviour; the Lord lives and grants victory to his anointed.

The selected verses (2-3a, 3b-4, 47, 51ab) with the response “I love you, Lord, my strength” concentrate the psalm’s opening and closing notes of love and trust. The psalmist declares his love for the Lord as strength, rock, fortress and saviour. God is the rock of refuge, shield, saving strength and stronghold. He cries out in praise and is saved from his foes. The Lord lives; blessed be the Rock. The God of salvation is to be exalted, for he gives great victories to his king and shows merciful love to his anointed. The tone is intimate and royal at once: personal affection joined to public thanksgiving for covenant faithfulness.

In the Roman Catholic Lectionary, these verses are appointed as the Responsorial Psalm for the 30th Sunday in Ordinary Time, Year A. The First Reading (Exodus 22:20-26) commands care for the alien, widow and orphan, and warns that God hears their cry, for he is compassionate. The Second Reading (1 Thessalonians 1:5c-10) praises a community that received the word in affliction with joy and became a model of faith. The Gospel (Matthew 22:34-40) gives Jesus’ summary of the law: love of God with all the heart, and love of neighbour as oneself.

Psalm 18 gathers these themes. Its opening cry of love for the Lord as strength answers the first and greatest commandment. The God who is rock and refuge is the same compassionate Lord who hears the cry of the vulnerable in Exodus. Victory given to the anointed points beyond David to Christ, in whom love of God and neighbour is perfectly fulfilled. For the assembly, the psalm turns Ordinary Time into an act of grateful love. It invites worshippers to confess the Lord as their strength, to trust his saving help, and to let that love overflow towards neighbour. The response “I love you, Lord, my strength” becomes both personal prayer and communal profession of the two great commandments.