Exodus 15:9

The enemy said, I will pursue, I will overtake, I will divide the spoil; my lust shall be satisfied upon them; I will draw my sword, my hand shall destroy them.

The verse records the boastful resolve of the Egyptians to chase Israel, catch them, seize their goods and persons as spoil, satisfy their desire upon them, and wipe them out by sword and power.
It stands inside Israel's song of triumph after the sea was parted for their deliverance, exalting God as their strength and salvation who redeemed and led them, in direct contrast to the enemy's plan.
God turned that planned triumph upside down by saving Israel and drowning Pharaoh's pursuing army, causing the waters to close over them so their boasting came to nothing.
The outcome shows that in the crisis at the Red Sea Israel could safely trust in God.
Preserved by command as a memorial of that care and deliverance to be taught to the children, the song was sung by the whole host with Moses and Miriam, fixing its lessons in memory, lifting minds above trial, strengthening faith, and uniting the people to God and to one another as they journeyed.

Boast Within Triumph Song

The boast records the enemy's confident and boastful resolve to chase Israel down, catch them, and carry out vengeance upon them. He meant to overtake the fugitives, divide the spoil, and seize both the people themselves and their goods and possessions for himself. His lust and desire would be satisfied upon them, and then he would draw the sword and destroy them by sword and by his own hand.

This defiant purpose stands inside Israel's song of triumph sung after the sea was parted and the people were delivered at the Red Sea. It is the song that celebrates God as Israel's strength and salvation, who redeemed the people and guided them, and that gives Him glory for the deliverance wrought for them. Its force lies in the contrast, setting the enemy's confident plan to pursue, seize the spoil, satisfy desire, and destroy against God's triumph over him. That the Egyptians dared to pursue Israel into and through the sea showed how sure they felt of victory.

God Overwhelms Pursuing Army

The boast of pursuit, overtaking, dividing spoil, seizing the people with their possessions, satisfying desire upon them, and destroying them by sword and hand was overturned when God delivered and saved Israel while overwhelming the Egyptian army at the Red Sea. The Egyptians pursued Israel intending to overtake and destroy them, but God intervened, Pharaoh's forces were drowned, and the pursuing army perished. That reversal turned threatened destruction into Israel's song of triumph after deliverance.

The Lord overthrew the confident enemy when He caused the sea to cover them, and the waters closed over those who had pursued through the sea feeling sure of victory. Their plan to pursue, overtake, seize spoil and goods, satisfy desire against the people, and destroy them by force and sword therefore came to nothing.

The verse belongs to the song celebrating God as Israel's strength and salvation, who redeemed and guided the people, and the Red Sea crisis in which the boastful intent to pursue, seize spoil, satisfy desire, and destroy was defeated shows that Israel could safely trust in God.

Song Preserved for Worship

The boast is preserved within the sacred song of triumph sung after Israel's deliverance at the Red Sea from Pharaoh's army. The whole host of Israel sang it together in triumph. Miriam led the song and Moses joined in it. Moses was commanded to shape the song out of the events of the deliverance, so that the enemy's boast remains as part of the history to be taught to children and remembered as a memorial of divine care and deliverance.

Sung together as the people journeyed through the wilderness, the song fixed precious lessons in their minds and lifted their thoughts from the trials and difficulties of the way. It soothed and calmed the restless, turbulent spirit, implanted principles of truth in the memory, and strengthened faith. By concert of action it taught order and unity and brought the people into closer touch with God and with one another.