Psalm 100 (99 in the Septuagint and Vulgate numbering) is a short but exuberant hymn of praise, often called a “psalm of thanksgiving” or an “entrance psalm.” It is anonymous, though ancient tradition sometimes links it to David. Scholars generally date it to the post-exilic period (6th–5th century BC), when the returned exiles were rebuilding the Temple and re-establishing worship in Jerusalem. It belongs to a group of psalms (93–100) celebrating the universal reign of God. Its simple, joyful structure suggests it was sung by pilgrims entering the Temple courts, possibly as a processional or call to worship.

The selected verses (1-2, 3, 5) with the response “We are his people, the sheep of his flock” form a perfect invitation to communal praise. It calls “all the earth” to “cry out with joy to the Lord,” to “serve the Lord with gladness,” and to “come before him, singing for joy.” The central verse reminds worshippers of their identity: “Know that he, the Lord, is God. He made us; we belong to him. We are his people, the sheep of his flock.” The psalm concludes with a declaration of God’s goodness, eternal merciful love, and faithfulness from age to age. This creates a movement from universal summons to intimate belonging and confident trust.

In the Lectionary, these verses are appointed as the Responsorial Psalm for the 11th Sunday in Ordinary Time, Year A. The readings for this Sunday focus on God’s initiative in calling and sending His people: the First Reading (Exodus 19:2-6a) presents Israel as a kingdom of priests and holy nation; the Second Reading (Romans 5:6-11) speaks of God’s reconciling love; and the Gospel (Matthew 9:36–10:8) shows Jesus’ compassion for the crowds “like sheep without a shepherd” and His commissioning of the Twelve.

Psalm 100 beautifully unites these themes. The image of God’s people as the sheep of His flock echoes Jesus’ shepherd-like care and the mission of the apostles. The call to joyful service and recognition of God as Creator reinforces the covenant identity proclaimed at Sinai and fulfilled in the Church. For the assembly, the psalm transforms Ordinary Time into an opportunity for renewed gratitude and mission. It reminds believers that, as God’s flock, they are chosen not for privilege alone but to proclaim His merciful love and faithfulness to the world. In a secular age, it encourages the Church to enter God’s presence with gladness and to live as a holy, priestly people sent to gather the scattered.