“As the years pass, God expands the land promise to extend beyond Canaan to eventually encompass the entire world.
“The first hint is the varying descriptions of the geographic boundaries of the Promised Land throughout the Pentateuch (cf., e.g., Genesis 15:18-21; Exodus 23:31-33; Numbers 34:1-12; Deuteronomy 1:7; 11:24; 34:1-4; Joshua 1:2-4). Such variety suggests the borders of the land are intended to expand as Israel dwells there and exercises dominion over it and the surrounding nations.
“A second indication is that God promised Abram descendants more numerous than the stars in the sky or the dust of the earth (Genesis 13:16; 15:5). Even allowing for the possibility of hyperbole, the sheer number of descendants envisioned seems to demand a larger territory than the land of Canaan.
“A third indication comes from Romans 4:13, where Paul asserts that God promised Abraham and his offspring that he “would be heir of the world.” The apostle, following the lead of the prophets, sees in nascent form a promise that encompassed all of creation. The frequent descriptions of the fertility and fecundity of the land portray it as a new Edenic Paradise where God’s original purposes for creation will be realized.”
Harmon, Matthew S.. Rebels and Exiles (Essential Studies in Biblical Theology) (p. 22). InterVarsity Press. Kindle Edition.