What does Psalm 9:2 mean?
David expresses his joy in the Lord. Already he has celebrated God's actions (Psalm 9:1). Here, he is thankful for God Himself, and he finds in the Lord a source of great joy. This psalm acclaims God's role in Israel defeating her attacking enemies (Psalm 9:3–6).This verse addresses the Lord as "Most High." This is the same name for God which Melchizedek used when he blessed Abram and praised God (Genesis 14:19–20). It is also the name Abram employed when he refused a reward offered by the King of Sodom. He rightly identified God as "God Most High" and described him as "Possessor of heaven and earth" (Genesis 14:22). When a believer perceives God as sovereign of heaven and earth, he will praise Him and rejoice in Him.
In Philippians 4:4 Paul repeatedly exhorts his readers to rejoice in the Lord. This came in the context of two women, Euodia and Syntyche, who were at odds with each other (Philippians 4:2–3). They needed to remove their attention from what divided them, focusing instead on the blessings they both had in the Lord.