Deuteronomy 32:9

For the LORD’s portion is his people; Jacob is the lot of his inheritance.

The Lord's portion is His own people, with Jacob as the allotted share of His inheritance, His chosen possession kept for Himself when He divided the nations their inheritance and set the bounds of the peoples according to the number of the children of Israel.
It stands in Moses' closing song that rehearses God's past dealings with Israel and foretells future events, proclaiming Him the Rock whose work is perfect and whose ways are judgment, just and right.
He found them in a desert waste, led them about and instructed them and kept them as the apple of His eye, bearing them as an eagle bears its young, alone leading them with no strange god with them, redeeming them from bondage in Egypt and carrying them through the wilderness into the promised land.
The verse declares His infinite love, that they are precious to Him and His church remains the dearest object on earth to Him, chosen not for their benefit alone but to reveal His kingdom and restore His image as a light to the world.
Set amid warnings that calamity follows persistent rebellion and promises of final victory, belonging to Him calls for gratitude, humble devotion and cheerful thanksgiving, with His past goodness often recounted to young and old.

Song Setting and Nations Divided

The verse belongs to Moses' closing song that sums up God's past dealings with Israel and rehearses what was to come. That song recounts how God had dealt with His people in the past and foreshadows future events, including the final victory of the faithful when Christ returns in power and glory.

The song was taught to the whole nation, including children, as a continuing lesson to warn, correct, restrain and encourage them. It was preserved as a record of God's dealings with ancient Israel so the people could teach their children and remember His care and deliverance. God commanded Moses to frame it out of His dealings with ancient Israel so the history of the past would not be forgotten. It sets up waymarks and gathers memorials and lays them up in sight, giving parents what to teach their children, so that when children inquire the whole story of God's providential dealings, marked goodness, mercy, care and deliverance of His chosen people can be repeated.

When the Most High divided to the nations their inheritance and separated the sons of Adam, He set the bounds of the peoples according to the number of the children of Israel, keeping Israel for Himself as His own portion and inheritance. He set the nations' boundaries with Israel in view, then took Israel for Himself. Its setting declares Him the Rock whose work is perfect and whose ways are judgment, a God of truth without iniquity, just and right, whose doctrine drops as rain and distills as dew to publish His name.

The Lord's Beloved Inheritance

Jacob, that is Israel, is the Lord's own portion and the lot of His inheritance, His chosen possession and vineyard, His treasured inheritance and elect.
The verse expresses His love for His people.
They are precious to Him and dear to His heart, loved with infinite love, and His church is the dearest object on earth to Him.

He found Jacob in a desert land and waste howling wilderness and made him His personal charge.
He led him about and compassed him about, cared for him, instructed and taught him, and kept him as the apple of His eye.
Like an eagle that stirs up her nest, flutters over her young, spreads abroad her wings, takes them and bears them on her pinions, He tended and carried them with close, tender, personal care, and He alone led them with no strange god with Him.

He redeemed them from bondage in Egypt by power and mercy, with Christ Himself as their leader enshrouded in the pillar of cloud by day and pillar of fire by night.
He miraculously preserved them through the perils of the wilderness wandering, giving water from the rock and manna, until He brought them into the land of promise to dwell as under the shadow of the Most High as a favored nation.
This choosing and leading was not for their benefit alone but to prepare the way for His light to the whole world, to reveal the principles of His kingdom and restore the moral image of God in man as an object-lesson to the surrounding nations that knew not God.

Warning, Hope and Response

The song stands set against prophecies of judgment upon disobedience, exposing the conditions of departure from God and warning that calamity swiftly follows persistent rebellion. It does not end with judgment only, for it recounts past dealings in order to foreshadow future events, including the final victory of the faithful when Christ returns in power and glory.

What was true of Jacob remains true of God's elect, His church on earth today. Though the world may condemn and oppress them, they remain dear to God, and He will not allow His heritage to be oppressed. By sin man lost connection with God and has of himself no means of salvation, yet in Christ those called out of darkness into marvelous light to show forth His praise and to shine as lights amid the darkness of the world are brought nigh unto the Father and made His portion.

Belonging to Him and living under such care calls for gratitude, humble devotion and cheerful thanksgiving. It calls for giving Him more than has yet been given and for choosing allegiance to God rather than to unbelievers. Remembering this history shows obedient commandment-keeping people that they are the Lord's portion and inheritance, giving reason for joy and gladness and moving them to claim His blessing with praise and thanksgiving for the glory of His name. He is the Fountain of life and power who can make the wilderness a fruitful field and who still works as a wonder-working God, and this past history of goodness and wonderful works needs often to be brought before young and old.