Why is the area the children of Israel were eventually led to, after being freed from bondage, referred to as the Promised Land? God mentioned this area when he told Moses, through a burning bush, what he would accomplish through him (Exodus 3:7 - 8).
God, while the children of Israel were still in Egypt, referred to the territory they would inherit when he stated, "And it shall be when you have come to the land which the Lord will give you, according as He has promised that you shall keep this service (the Passover - Exodus 12:25).
Several times Moses referenced promises that involved the Israelites.
Listen to them (God's laws, commandments and judgments) . . . and you will become a mighty nation and live in that rich and fertile land, just as the Lord, the God of our ancestors, has promised (Deuteronomy 6:3).
And you shall engrave upon them all the words of this law when you have passed over so that you may go in to the land . . . as the Lord God of your fathers has promised you (Deuteronomy 27:3, see also 9:23, 26 - 28).
The book of Genesis informs us the idea of a guaranteed inheritance originated with God making a covenant with the patriarch Abraham. He informed the father of the faithful, "I will give to you and to your descendants this land in which you are now a foreigner. The whole land of Canaan will belong to your descendants forever" (Genesis 17:8).
God told Abraham that he and his descendants would be given the area known as Canaan. Because of Abraham's faith and obedience, he and his children would be given a place to live not just as a gift, but as an inheritance! The New Testament reaffirms this promise made by the Eternal (see Hebrews 11:8 - 9).