Psalm 21 is Psalm 20 that has been regrouped. Psalm 21 is Psalm 118 that was split into two to better fit the Psalter, which had 150 Psalms. Psalm 21 begins “Give victory to the king” and goes on with a pleas for God to help someone succeed in battle. The Psalmist describes his enemies and how they attack him. Psalm 21 ends with a plea for deliverance from the Lord God, and to come to the House of the Lord and worship. Psalm 21 ( Psalm 20) is part of one of the five Songs of Ascents ( Psalms 120-134 ).
The Psalms were songs that were used for praise and worship of God. Psalm 21 is one of the Psalms that makes mention to David, which at the time was King of Israel. This Psalm is asked for someone to be exalted and praised and that enemies should be destroyed. The Psalter ( Psalms 120-134 ) were five songs sung by Jewish people travelling to Jerusalem to worship. Psalms 120-134 were called the Songs of Ascents because people would go up to Jerusalem on pilgrimages and they would walk up the hill to get there.