In Genesis 23, Abraham went to great lengths to secure a small plot of land to bury his wife, Sarah. That land stake was a further indication of his faith in God's promises. Abraham believed that God would indeed fulfill all his promises previously made in covenantal relationship with him as the father of God's people. Each of God's promises were expressed so that we should expect a greater Divine glory in the way they are fulfilled.
In Genesis 12, God called Abraham to follow him to the land that he would show him. That land was Canaan. He told Abraham that he would be a great nation with a great name and would be a blessing to all nations. He told Abraham that blessing or cursing for others would be based on how they blessed or cursed him.
Obviously, none of the promises would come to fruition if Abraham did not have offspring. He needed an heir to inherit the land, to build into a nation, and in all of that to be a great blessing to the nations. Abraham commenced his faith in God's promise by trying to control his finite circumstances. On two occasions Abraham put forward a scheme to supply his own heir to bring about the promises of God. This wasn't to be.
In Genesis 15, God's promises to Abraham were given in expanded glory. Abraham was not just to become a nation, but from his very own son would have descendants more numerable than the stars in the sky (v. 4-6). There is something so wonderful about God's promise of offspring for Abraham. Through Abraham's offspring (singular) there will be countless offspring (plural).
In this same chapter, God gives expanded detail on the land. He says that Abraham's offspring will be sojourners in the land until the people of the land who do not serve him will come under his judgment. The description of this land was from the river of Egypt to the river of the Euphrates (v.18). The expectation we receive from Genesis 15 is that God is building a great people for himself who will dwell with God in a peculiar holiness and separated from the ungodliness of the world. In some way this will be a blessing to the entire world.
In Genesis 22, we end up being left with no doubt that these promises would be fulfilled in a Son of Abraham greater than his immediate son, Isaac. God certainly showed a picture about how he would bring about his promises through Isaac. It would come through the sacrifice of God's only Son in Abraham's line. This greater one would be the fulfillment of the greater expectation of these promises. The blessing and land would be greater in the greater Offspring.
Throughout the Old Testament, we get this indication on an ongoing basis. In Israel's disobedience, they were thrown out of the land and the prophets often expected Israel's repentant return to God's inheritance. With that, the Old Testament prophets also speak of an expansion of Israel beyond its previous borders to include the nations in the promised blessing.
Isaiah 54:1-3 "Sing, O barren one, who did not bear; break forth into singing and cry aloud, you who have not been in labor! For the children of the desolate one will be more than the children of her who is married," says the LORD. 2 "Enlarge the place of your tent, and let the curtains of your habitations be stretched out; do not hold back; lengthen your cords and strengthen your stakes. 3 For you will spread abroad to the right and to the left, and your offspring will possess the nations and will people the desolate cities.
Isaiah 26:15 But you have increased the nation, O LORD, you have increased the nation; you are glorified; you have enlarged all the borders of the land.
Isaiah 27:6 In days to come Jacob shall take root, Israel shall blossom and put forth shoots and fill the whole world with fruit.
Daniel 7:13-14 "I saw in the night visions, and behold, with the clouds of heaven there came one like a son of man, and he came to the Ancient of Days and was presented before him. 14 And to him was given dominion and glory and a kingdom, that all peoples, nations, and languages should serve him; his dominion is an everlasting dominion, which shall not pass away, and his kingdom one that shall not be destroyed.
Psalm 2:8 Ask of me, and I will make the nations your heritage, and the ends of the earth your possession.
Micah 5:4 And he shall stand and shepherd his flock in the strength of the LORD, in the majesty of the name of the LORD his God. And they shall dwell secure, for now he shall be great to the ends of the earth.
Zechariah 9:10 I will cut off the chariot from Ephraim and the war horse from Jerusalem; and the battle bow shall be cut off, and he shall speak peace to the nations; his rule shall be from sea to sea, and from the River to the ends of the earth.
In the book of Acts, we see Israel coming back into the land from their dispersion all across the land.
Acts 2:5, 9-11 Now there were dwelling in Jerusalem Jews, devout men from every nation under heaven. ... 9 Parthians and Medes and Elamites and residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, 10 Phrygia and Pamphylia, Egypt and the parts of Libya belonging to Cyrene, and visitors from Rome, 11 both Jews and proselytes, Cretans and Arabians--we hear them telling in our own tongues the mighty works of God."
In the book of Acts, we also see the expansion of the borders in the great commission.
Acts 1:8 But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth."
As we continue to read in the book of Acts, we find statement of amazement that Gentiles across the nations are also being included in God's people. There are many examples, here are just two.
Acts 10:45 And the believers from among the circumcised who had come with Peter were amazed, because the gift of the Holy Spirit was poured out even on the Gentiles.
Acts 14:27 And when they arrived and gathered the church together, they declared all that God had done with them, and how he had opened a door of faith to the Gentiles.
In the New Testament there are no texts that give any indication that the borders of the land for God's people would ever again be restricted to the borders of the land of Canaan. The New Testament expectation is that in Christ, the ultimate Offspring, blessing, multiplication of offspring, and land would be a spreading phenomena of God's glory across the entire earth. It would not only be a spreading phenomena of physical land but an inclusion of both Jew and Gentile as God's called out people.
Aso in the New Testament we await God's final judgment of the wicked out of the land of the entire earth and the final consummation of all things when God's people will finally dwell with him in the perfection of the land forever.
This is the greater glory that Abraham always expected (Hebrews 11:8-16). How amazing that this expectation is seen in something as humble as buying a piece of land for a burial plot for your wife.