Psalm 23, often titled "The Lord is my shepherd," is one of the most beloved passages in the Bible, offering profound comfort and assurance of divine providence. This poetic psalm, part of the Book of Psalms in the Hebrew Bible and Old Testament, employs the metaphor of a shepherd caring for his flock to depict God's guidance, protection, and sustenance. Its verses transition from pastoral imagery—green pastures and still waters—to themes of facing peril in the "valley of the shadow of death," culminating in eternal dwelling in the Lord's house. The refrain, repeated in the responsorial form, emphasises unwavering trust: "The Lord is my shepherd; there is nothing I shall want."

Regarding its origins, Psalm 23 is traditionally attributed to King David, the shepherd-boy turned monarch, around 1000 BC. David, drawing from his early experiences tending sheep, likely composed it during his maturity as king, reflecting on life's trials and God's faithfulness. Some scholars, however, propose a post-exilic date (after 539 BC), suggesting it emerged from Israel's collective experiences of exile and restoration, though the Davidic authorship remains widely accepted in religious traditions. Historical contexts vary; one view links it to David's flight during Absalom's rebellion, symbolising refuge amid betrayal and danger.

In the liturgy, Psalm 23 holds particular significance as the responsorial psalm for the Mass on the Fourth Sunday of Lent in Year A. This Sunday, known as Laetare Sunday, marks a midpoint in Lent with themes of joy amid penitence. The psalm complements the readings: the First Reading from 1 Samuel recounts David's anointing as king, echoing the shepherd motif; the Gospel from John 9 describes Jesus healing the man born blind, portraying Christ as the light and shepherd who restores sight and soul. During Lent, a season of reflection and spiritual journey, Psalm 23 reassures believers of God's presence in "dark valleys," fostering trust and hope in divine mercy. It invites the faithful to envision Jesus as the Good Shepherd, guiding through trials towards Easter's resurrection light, making it a fitting meditation on renewal and eternal life. Thus, in this liturgical context, the psalm bridges Old Testament imagery with New Testament fulfilment, encouraging communal response in worship.