What does the Bible mean when it says, "all first born sons belong to God?"

Westminster Confession of Faith Chapter 2 Article 2

The sermon explores the nature of God as self-sufficient and sovereign, drawing from Westminster Confession of Faith and Scripture to demonstrate that God's actions stem from His own pleasure, not from a need for creation. It examines the implications of God's self-sufficiency, asserting that He is good independently of human response and capable of both salvation and judgment, ultimately highlighting the joy and grace He extends while acknowledging the mystery of His will. The passage from 1 Samuel 1 underscores Hannah's dedication of her son Samuel to the Lord, illustrating a covenantal understanding of firstborn sons and foreshadowing the ultimate fulfillment of this concept in Jesus Christ, who embodies God's sovereignty and offers redemption to humanity.