Psalm 27, traditionally attributed to King David, is a profound hymn of trust in God amid adversity. Its superscription "Of David" links it to the poet-king's life, likely composed during a period of peril, such as pursuit by enemies or the rebellion of Absalom. Scholars debate whether it is one unified psalm or two originally separate ones combined: verses 1–6 express bold confidence and devotion to the Temple, while 7–14 shift to earnest petition and hopeful waiting. Pre-exilic dating is favored due to its focus on the Jerusalem Temple and themes of refuge.

The psalm opens with the iconic declaration: "The Lord is my light and my salvation; whom shall I fear?" portraying God as illuminator, deliverer, and fortress. The psalmist longs to dwell in God's house, gazing on divine beauty, and concludes with faith: "I believe I shall see the Lord’s goodness... Wait for the Lord; be strong."

In the liturgy, Psalm 27 is frequently used, appearing in the Liturgy of the Hours (divided at Vespers) and as a responsorial psalm at Mass, including funerals for its message of hope. For the 3rd Sunday in Ordinary Time, Year A, selected verses (1, 4, 13–14) with refrain "The Lord is my light and my salvation" perfectly complement the readings: Isaiah 8:23–9:3 proclaims light dawning on a people in darkness (Zebulun and Naphtali), fulfilled in Matthew 4:12–23 where Jesus begins his ministry in Galilee, calling disciples and proclaiming the Kingdom. The psalm reinforces this theme—God as light overcoming fear and gloom—inviting the assembly to trust in Christ's salvific presence and patiently await his goodness in daily life.

This responsorial form encourages communal prayer, echoing ancient Temple worship while affirming Christian hope in God's enduring protection.