The Catechism in Questions & Answers

717. What references are there to prayer in the Old Testament?

There are many references to the worship of God in the Old Testament. The hymn of Moses serves as a good example: “For I proclaim the name of the Lord: ascribe greatness to our God. He is the Rock, His work is perfect; for all His ways are justice, a God of truth and without injustice; righteous and upright is He” (Deuteronomy 32: 3-4).
The most important endeavour of the Psalms is to give thanks to God in prayer, and to bring Him praise and glory. The Old Testament also contains many references to prayers that implore the help and support of God.