Psalms 136:15 (KJV) says, "But overthrew Pharaoh and his host in the Red sea: for his mercy endureth for ever."

This verse comes from a psalm of thanksgiving, in which the psalmist repeatedly declares, "for his mercy endureth for ever." The psalmist highlights various acts of God's mercy and his deliverance of the Israelites from their enemies. In this particular verse, the psalmist refers to the overthrow of Pharaoh and his army in the Red Sea.

The context of this verse is the exodus of the Israelites from Egypt. After enduring years of slavery and oppression, the Israelites were finally delivered by God through his servant Moses. As they fled from Egypt, Pharaoh changed his mind and pursued them with his army. The Israelites found themselves trapped at the edge of the Red Sea with Pharaoh's army closing in on them. In their moment of desperation, God miraculously parted the waters of the Red Sea, allowing the Israelites to cross on dry land. When Pharaoh's army followed them, the waters returned and drowned the pursuing Egyptian soldiers, effectively delivering the Israelites from their oppressors.

The theme of this verse is the enduring mercy and deliverance of God. It emphasizes the faithfulness and power of God in protecting his people and overthrowing their enemies. The psalmist uses the phrase "for his mercy endureth for ever" as a refrain to remind the reader of the unwavering and everlasting nature of God's mercy.

The symbolism in this verse is powerful and multi-layered. The Red Sea symbolizes the barrier or obstacle that stood between the Israelites and their freedom. It represents the challenges and struggles that we all face in our lives. The overturning of Pharaoh and his army in the Red Sea symbolizes the defeat of evil and oppression by the power of God. It serves as a reminder that no obstacle is too great for God to overcome, and no enemy is too powerful for God to defeat.

Furthermore, the Red Sea can also be seen as a symbol of baptism and rebirth. Just as the Israelites emerged from the Red Sea as a free people, believers emerge from the waters of baptism as new creations, cleansed and redeemed by the mercy and power of God.

Overall, Psalms 136:15 (KJV) is a powerful reminder of God's enduring mercy and deliverance. It serves as an encouragement to believers, reminding them that God is faithful to protect and deliver them from their enemies and from the challenges they face. The symbolism of the Red Sea and the overthrow of Pharaoh and his army further emphasizes the transformative and redemptive power of God in the lives of his people. This verse continues to be a source of hope and inspiration for believers, pointing them to the unchanging and unwavering nature of God's mercy.